#Seiko number lookup serial numbers
Some serial numbers of the earliest Seiko 6139s indicate a production date of March 1969 or even as early as February 1969, but it is unclear if these are samples or were the first ones intended for the Japanese market. On the other hand, the Chronomatic group started production and release to the world’s retail markets in June or July of 1969, and Zenith’s chronograph was released into the wider world market in October 1969. These early watches were to be released to the Japanese market only. Last but not least, Seiko lays claim to the title by being the first to start serial production of their 6139 “Speed Timer” in May 1969. The Chronomatic group was also the first to show several models of pre-production samples during the Basel Fair in April of 1969, a more impressive showing when compared to Zenith, who had fewer samples during the same event. The group laid claim to the title by introducing the Chronomatic prototypes on March 3, 1969, in a much-highlighted press event. The companies created a mutually beneficial partnership and worked together in developing their automatic chronograph. The second contender was a collective of watchmakers, which could be termed the Chronomatic group, namely Heuer, Breitling, and Hamilton-Buren.
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The company even named their automatic chronograph the “El Primero” or “The First” in Spanish. The first watch company to lay claim to the title was Zenith, who introduced their first prototypes on January 10, 1969. Back in 1969, several big names were competing for the title of the world’s first automatic chronograph. There is still debate in terms of which watch holds claim to the title of world’s first automatic chronograph, but really, it all boils down to which type of “first” you would consider most appropriate.
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45KS (and also 45KSC for the calendar model, 45KM and KCM for chronometers) had several different case and dial combinations with their own individual numbers as did many other lines.
#Seiko number lookup series
62MAS was specifically 62MAS 010 (62 movement series Matic Special watch, 800X dial and 800X case, but there was only ever the one model). It's just that no one remebers them without checking the old catalogs (which are mostly around only for JDM models anyway), with some notable exceptions. They did, often a few numbers and letters derived from a combination of movement, lineup and specs, and then numbers to identify the specific model (so a unique combination of case and dial). Although older Seikos usually didn't have one