Don't miss the next drop
This might be one of the most compelling Omegas we have ever offered, and the reason has nothing to do with rarity for rarity’s sake. It has to do with timing, in every sense of the word. The Omega Seamaster Calendar ref. 2627, launched in 1952, is widely recognized as the first Omega wristwatch to feature a date complication. It housed the cal. 353, a bumper automatic derived from the legendary 28.10 RA, fitted with a date module. Every known production example of the 2627 carries “Seamaster” and “Calendar” branding on its dial, with the exception of a small number produced for the American market. This watch carries neither.
What we have here is a transitional assembly that predates the formal Seamaster Calendar launch. The case itself is a 2627 case, but it is fitted with the older 2438-2 caseback, stamped with that earlier reference number. The standard 2438-2 was a time-only bumper automatic from the mid-1940s housing the cal. 28.10 RA, with no provision for a date complication. Open this caseback and you will find not a 28.10 RA but a cal. 353, the very same date-equipped movement that would go on to power the Seamaster Calendar. The movement serial number, 12161709, dates to approximately 1950 to 1951, placing this watch firmly in the window between the 353’s introduction and the 2627’s official commercial debut. The dial features a date aperture at 6 o’clock and reads simply “Omega Automatic” with “Swiss Made” at the bottom. It is entirely original and unrefined, with no evidence of added printing or removed text. The inner caseback also carries a machine-stamped “141” that sits inverted relative to all other markings. The depth and uniformity of that stamp rules out a casual watchmaker’s service mark. Its inverted orientation indicates it was applied at a separate production stage, consistent with the caseback being selected to pair with the new 2627 case and date-equipped dial and movement.
The picture is clear: this is an Omega assembled during the transitional period when Biel was preparing to launch its first ever date watch. A new 2627 case, an older 2438-2 caseback repurposed from existing stock, the new cal. 353, and a date dial produced before the Seamaster Calendar branding was finalized. Every observable detail supports this conclusion. The movement serial places it in 1950 to 1951. The dial carries no Seamaster or Calendar text. The caseback reference predates the 2627 line. And the inverted “141” stamp points to a deliberate production decision rather than an aftermarket modification. An Extract of the Archives from the Omega Museum has not yet been obtained and is strongly recommended for the next owner, but the evidence on the watch itself tells a consistent and unambiguous story. This watch predates the official launch of Omega’s first date watch.
This particular example wears its seven decades with honest grace. The cream dial has developed a gentle warmth, and the applied gold dagger and arrow hour markers show their age through softened edges and lume that has aged to a rich, oxidized tone. The dauphine handset is original. The stainless steel case shows honest wear consistent with a watch that was worn and enjoyed, with surface marks on the lugs and bezel, though nothing that compromises the overall integrity of the case shape. The signed Omega crown is original.
We are presenting this piece on an OTTUHR ostrich strap with green contrast stitching and an OTTUHR signed buckle. For the Omega collector, the early calendar collector, or anyone drawn to watches that sit at inflection points in horological history, this is an extraordinary opportunity. Watches like this do not surface with explanations attached. This one does.
