A 1961 Omega Seamaster 14704 SC-61 Cal. 591 on a Bonklip Bracelet

The Watch: Omega Seamaster 14704 SC-61 (1961)

This reference 14704 SC-61 houses the caliber 591 automatic movement, part of Omega’s evolution into mid-century, thin-profile automatic watches. With 20 jewels, a bidirectional winding rotor, and a smooth sweep, the 591 represents the refinement of Omega’s pre-COSC movements before the later chronometer-grade calibers dominated the lineup.

The dial is particularly striking: an “Explorer” style 3-6-9 layout, reminiscent of tool watches of the era but paired here with the elegant Seamaster script. The patinated lume plots at the numerals and dagger indices reflect natural aging, a prized trait for collectors today.

The case, stamped 14704 SC-61, is stainless steel with a screw-down Seahorse caseback, engraved with the emblem that became synonymous with the Seamaster line. The crown carries the correct Ω logo, and the overall design balances utility with understated mid-century elegance.

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From the Dirty Dozen to the Seamaster

Omega’s connection to military tool watches runs deep. During World War II, Omega supplied thousands of wristwatches to the British Ministry of Defence, including their contribution to the famed “Dirty Dozen” issued to the Allied forces. Those watches were simple, durable, and resistant to the harsh conditions of war.

Post-war, Omega leveraged this military expertise when launching the Seamaster line in 1948, designed as a civilian waterproof watch with military DNA. The early Seamasters borrowed from the hermetically sealed cases and durable construction developed during wartime. The 14704 carries this lineage forward—rugged enough for daily wear, yet elegant enough for post-war prosperity.

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The Bonklip Bracelet: WW2 Innovation, Postwar Utility

The Bonklip bracelet, first patented in the 1920s and popularized through the 1930s–40s, was widely used by RAF pilots and military personnel during World War II. Its stainless steel ladder-link design offered several advantages:

• Lightweight and breathable in hot, humid climates.

• Instant adjustability, allowing the bracelet to be worn over uniforms.

• Corrosion resistance, crucial in tropical deployments.

For these reasons, Bonklip bracelets became synonymous with military-issued tool watches.

Pairing a 1961 Seamaster with a Bonklip bracelet is period-correct and historically meaningful. While leather straps often degraded in tropical service, Bonklip bracelets endured. Collectors today appreciate the practical elegance of this combination, which ties directly back to Omega’s wartime legacy.

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Technical Specifications

• Reference: Omega Seamaster 14704 SC-61

• Year: 1961

• Movement: Omega Cal. 591, automatic, 20 jewels

• Case: Stainless steel, screw-down Seahorse caseback

• Dial: Explorer-style 3-6-9 dial with applied indices, luminous plots

• Crystal: Acrylic (hesalite)

• Bracelet: Bonklip stainless steel

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A Watch of Continuity

This Seamaster tells a story: from Omega’s wartime production of robust tool watches, through the civilian boom of the Seamaster line, to the enduring practicality of the Bonklip bracelet. It is a piece where history, engineering, and aesthetics converge—a mid-century timepiece that remains as practical today as it was over sixty years ago.

Images above: The crisp white dial with Explorer numerals, the copper-toned cal. 591 movement, the Seahorse caseback, and the period-correct Bonklip bracelet advertisement and patent drawing.

1955 Helvetia reference 351 (caliber 64 manual winding, sub-second movement)

Helvetia Watches: A Legacy of Swiss Craftsmanship

Helvetia Watches, renowned for their precision and elegance, has a storied history that intertwines with the iconic Swiss watch brand, Omega. Helvetia, the Latin name for Switzerland, perfectly represents the brand's commitment to Swiss horological tradition and craftsmanship.

In April 1892, Louis Brandt & Frere, a prominent Swiss watch company, registered the name 'Helvetia' as one of their brand names. During this period, they also introduced the name 'Omega' for a new line of high-quality lever movement pocket watches, showcasing their pioneering manufacturing techniques.

The success of Omega watches led the Brandt brothers to establish a new company in La Chaux de-Fonds called 'Société d'Horlogerie La Générale' in 1895. This move allowed them to allocate more resources to the production of Omega watches by transferring the manufacturing of their other watches to this subsidiary.

However, in 1911, Omega Watch Co decided to withdraw from La Générale, resulting in the official transfer of the registered brand names that were still under Omega's control.

During the 1950s to 1960s, Helvetia flourished in the era of dress watches, characterized by slim profiles and sophisticated aesthetics. The brand's dress watches from this period showcased exquisite craftsmanship and attention to detail - this example being no exception

Notably, Helvetia introduced the reference 64 movements, which were renowned for their precision and durability. Introduced during the 1950s, this hand-wound sub-second movement was renowned for its exceptional accuracy and reliability. The movement shows many similarities to contemporary Omega movements.

The caliber 64 movement emerged shortly after the introduction of the 830 family and showcased Helvetia's adaptability to the changing trends of the time. A larger 13.5 Ligne size reflected the growing preference for larger watches, while the caliber 64 movement was thinner than its predecessor, the 82C, making it ideal for slim dress watches of the era. With a frequency of 18,000 vibrations per hour, it provided precise timekeeping and powered numerous Helvetia timepieces.

This piece has a serial number on the inside back cover dating it to 1955:

I found this piece in a second-hand shop in Århus, and was drawn by its wonderfully patinaed dial, rose gold hands and markers and large sub-second dial. It's 35 mm was large for the time, and the narrow bezel makes it wear larger - it would certainly have stood out in the post-war years!

The movement is pristine, starts up with a few winds of the crown and is still accurate to within seconds a day - internal markings indicate that this watch was serviced and maintained. Fitted to an olive drab NATO strap this watch becomes informal, with the rose gold hands and markers highlighted by the contrasting olive green of the strap, but can quickly be transformed to a formal dress watch by fitting a dark brown Horween leather strap.

Rolex 1603 Sigma Linen dial - so... when is a dial rare?

I recently liquidized a fair portion of my vintage Seiko watch collection to acquire my first steel vintage Rolex - 1967 Rolex reference 1603 Sigma Linen dial. I chose it specifically for the "rare" combination of 1603-specific stainless steel machined bezel (most DateJusts have the white gold fluted bezel; reference 1601), pie-pan textile-like "linen" dial (most DateJusts do not have textured dials), and white gold "Sigma" indices and hands (most DateJusts have steel indices and hands). I like the utilitarian look and resilience of an all-steel DateJust (especially on an Oyster bracelet with the discretion (and corrosion resistance) of white gold hands and indices:

During my pre-acquisition search phase, I saw a Chrono24 ad calling a linen dial a "rare piece" and speculated what the definition of "rare piece" is. After some thought, I defined "rare" as:

A watch I can expect to see "once-or-less-in-a-lifetime" by chance 

...and had a basis to determine whether the combination 1603+Sigma+Linen is rare - or not.

I started with the date range of 160X four-digit Datejusts (1960 to 1979) and the serial numbers starting and ending this range (0,5M to 5.7M) for all references which gave 5M pieces produced, assumed (optimistically) 40% of all Rolexes made in this period were DateJusts (2M 16XX) produced of which half (1M) remain. I then checked Chrono24 to see the distribution of the various 160X references and dial types: 30% were 1603s, 4% 1603 Sigma, 3% 1603 Linen and 0.4% were 1603 Sigma + Linen dials. 

So - are the 4.000 remaining 1603 Sigma+Linen dials "rare" (by my definition)? 

Well, assuming 8B people globally and 4000 1603 Sigma+Linen dials, my calculation suggests there will be 2 million people for every 1603 Sigma+Linen (or 3 in Denmark -pop.6M - where I live). I asked Google how many people faces (or in this context - watch faces :-) I will see in a lifetime (ie. be within eye-identification-of-the-watch-on-their-wrist distance) and the estimate was 1,5M people. And with that, we have the number of 1603s I can expect to see in a lifetime as:

(1603: 56; 1603 Sigma: 8; 1603 Linen: 6 and 1603 Sigma+Linen: 0.75)

From this, I deduce that there might be 3 or so 1603 Sigma+Linen dials in Denmark (population about 6 million) but I'll be lucky to see one in a chance encounter in my lifetime... 

Of course, I'll now probably see a 1603 Sigma+Linen dial in the queue in Aldi tomorrow, and another next Thursday... I'll keep you posted!

1967 Rolex DateJust 1603 Steel Chronometer, Piepan Sigma Linen Dial

As an avid collector of 1960's Seiko watches, I have focused on the attributes that make Seiko watches attractive to me: the solid build quality which allowed these pieces to survive and be useable after more than 50 years, the cross-compatibility and availability of donor movements for maintenance and repair, industry-leading innovation, long and colorful brand history, classic design elements and extensive information available through books, forums, and blog posts.

One other brand provides all of the above and adds an additional attribute: a superlative brand image. That brand is Rolex. 

My passion for watches was kindled reading Rolex advertisements on the back cover of National Geographic as a youngster back in the late 1960s and early 1970s, and an aspirational dream was born to one day own a Rolex.

Life - and priorities - came in the way, but the aspirational dream remained. Eventually, I was able to indulge in the watch passion, and vintage Seiko offered an affordable entry into vintage watches. I read, researched, and blogged my way into building up themed collections, which I traded up for fewer, better pieces, but Rolex prices kept increasing, and the brand remained at arm's length for me. 

After nearly 20 years of collecting I was finally in a position to celebrate a professional aspiration (two years of successful self-employment), sold much of my existing collection, and acquired my first vintage Rolex: a 1967 Rolex DateJust 1603 with linen dial and 18K white gold coronet, markers  (sigma dial) and hands and stainless engine-turned bezel:

The 36mm Oyster case is a perfect size - perhaps THE perfect size for a "gentleman's steel wristwatch" and together with the jubilee bracelet, engine-turned bezel, and cyclops date lens possibly the quintessential Rolex wristwatch. The steel engine-turned bezel is a discrete, sober alternative to the shinier 18K white gold fluted bezel of the contemporary reference 1601 DateJust.

The chronometer-certified 26 jewel 1575 automatic movement running at 19800 bph is currently within 1 second a day - a tribute to the precision and durability of a 53-year-old watch. Much of this precision comes from the trademark Rolex free-sprung balance and Breguet overcoil which are less susceptible to positional variation and state of wind than conventional fixed-inertia regulator balances. Together with automatic winding, vintage Rolexes tend to be awesomely precise, decade after decade!

The trademark of the DateJust is the instantaneous date changeover at midnight, facilitated by a spring-loaded jeweled yoke operating a cam mounted on the reverse of the calendar wheel. The date function on these vintages is non-quickset and requires you to invest a few minutes and quite a bit of hand-turning to change the date, but this is an acceptable compromise allowing you to own a pie-pan linen sigma dial only found on these vintage four-number series pieces from the 1960s and early seventies... it's the price of admission to an exclusive club!

While much of the robustness comes from the overengineered 1575 movement, the classic Oyster case with its trademark screw-down case back and screw-down crown provides a water-and dustproof environment that has protected the movement and dial from the ingress of the elements for more than half a century.

Vintage Rolex watches are far from cheap, but is the price justified? For me it most definitely is. The 1603 Datejust is a "portable, tangible asset".

To be able to purchase this watch, I had to release ten vintage Seiko pieces from the collection I had carefully curated over the last 10 years. While it took me six months to sell my Seiko pieces and realize my initial investment in them, there are always ready buyers for a vintage DateJust, especially for less-common variants with linen- or sigma dials, and prices have steadily increased - doubling over the last decade, corresponding to a very reasonable 7% return on investment.

Tangible assets are however more than financial investments. In the DateJust I attained my aspirational goal, a watch that speaks to me, connecting me to my boyhood dreams and lifting my spirits every time I wear it. 

 

In a single watch, I have a design icon that defines the canon of perhaps the greatest design generation - 1950-60s RayBan Wayfarers, Levi 501s, Zippo lighters, Porsche 911s... and the Rolex DateJust.

As a design icon, the DateJust is perfect for everything from a t-shirt and jeans to a formal business suit, and as a portable asset I can - unlike say a classic car - wear and enjoy it, and have it lift my spirits all day, every day.

So yes, a vintage DateJust is absolutely worth it. 

Check out my Instagram profile for more pictures and impressions:

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A post shared by Harry Teicher (@watches_1964)

 

Seiko Gen 2 7T27-7A20 1995 British Royal Airforce (RAF) Military Issued chronograph

1995 Seiko Gen 2 (2nd Generation) Royal Air Force 

flight crew issued military analog chronograph

The 1995 Seiko Gen 2 (2nd Generation) Royal Air Force flight crew issued military analog chronograph was issued to Her Majesty’s armed forces from November 1990, following the issue of the Gen 1 quartz chronograph.

The caseback is inscribed with the "broad arrow" and NATO Stock Number (NSN) ‪6645-99 7683056‬ used for military-issued equipment:

6645 = Time Measuring Instruments
99 = NATO Country code United Kingdom
768-3056 = individual part number

In contrast to the commercial versions, the issued version has a 38mm case with a matte, bead-blasted finish, fixed strap bars and a "circle P” dial, indicating radioactive Promethium lume. 

The register at "12" is the 30 minute counter, the register at "6" is the continuous seconds and the register at "9" indicates the current hour on a 24-hour scale. 

The 7T27 (Gen 2) movement takes an SR927SW (395) 9.5 x 2.6mm battery.  

GEN1 (left) and GEN2 (right)

Seiko Gen 1 (1st Generation) 7A28-7120 Royal Air Force flight crew issued military analog chronograph

Seiko Gen 1 (1st Generation) 7A28-7120 Royal Air Force 

flight crew issued military analog chronograph watch 

The Seiko Gen 1 (1st Generation) 7A28-7120 Royal Air Force flight crew issued military analog chronograph watch was the first quartz chronograph watch issued to Her Majesty’s armed forces, with October 1984 being the first date of issue. 

This piece produced in August 1984 is thus one of the first issued of a total run of 11,307 Gen 1 chronographs, which were not replaced until November 1990.

The caseback is inscribed with the "broad arrow" and NATO Stock Number (NSN) ‪6645-99 7683056‬ used for military-issued equipment: 

6645 = Time Measuring Instruments
99 = NATO Country code United Kingdom
768-3056 = individual part number

In contrast to the commercial versions, the issued version has a 37mm diameter case with matte, bead-blasted finish, fixed strap bars and a "circle P” dial, indicating radioactive Promethium lume. 

The ‪3:00‬ o’clock register measures ‪1/10‬ths of a second, while the large center hand measure elapsed seconds.  The ‪9:00‬ o’clock register records chronograph minutes up to 30 while the bottom register is a continuous seconds hand.

The 7A28 (Gen 1) reference is Seiko's first analog chronograph, impressively over-engineered with metal gears and a 15-jewel movement which is able to be serviced and maintained. It takes a SR936SW (394) 9.5 x 3.6mm battery.

The Gen1 was originally issued on a nylon/leather Bund type (NSN 6645-99-527-7059) strap, which was later replaced with a nylon NATO (6B/2617, and NSN 6645-99-124-2986. Post war RAF straps also included the steel Bonklip (6B/2763 (17.5 mm), 6B/3224 (19.0mm), which were phased out in the early eighties but remained in issue until existing stocks were depleted.

1961 Omega Constellation "Pie Pan" Chronometer Full Set

1961 Omega Constellation "Pie Pan" Chronometer

This steel, no-date1961 Constellation was sold at Thule Air Base, Greenland in 1962, has the original Omega box, full papers and original Omega stainless steel bracelet with folding clasp, and boasts the chronometer grade, self-winding, 24 jewel caliber 551, adjusted to 5 positions and temperature.

On its beads-of-rice bracelet, this watch wears more substantially on the wrist than its 35mm, making it the ideal dress watch for special occasions!

1964 Rolex ref1002 Oyster Perpetual Chronometer

1964 Rolex Oyster Perpetual Chronometer

This 1964 Rolex Oyster Perpetual Chronometer is stunning, with its rarity and collectibility due in part to its Dauphine hands and original rivet bracelet, dated I-65.

There is no 7205 stamp on the back of the largest link (correct for the period) and the clasp blade is stamped with the year (1965) to match this. I have never used the original bracelet in order to preserve its pristine condition, and I wear this watch on an additional aftermarket Oyster bracelet for daily use.

The original tritium dial is correctly marked "T SWISS T" (for pre-1965) with tritium plots. The dial is in excellent condition, with minor age marks visible under the loupe. The rare Dauphine hands show signs of aging, visible under the loupe.

The cal 1560 with its Microstella screws and Bregeut free-sprung hairspring was used until 1965 in a number of chronometer-certified models, including the legendary Rolex 1016 Explorer and the Rolex 5512 Submariner. The movement is clean, and accurate to a few seconds a day.

This watch comes with an original Rolex box, cigarette card, Bucherer Rolex spoon as well as a 1960s advertisement extolling the Rolex Oyster Perpetual 1002 as the chronometer chosen by Sir Francis Chichester to accompany him on his single-handed circumnavigation of the globe in 1966.