
1975-Seiko-Catalog.V2, page 6
Reference unconfirmed — this watch’s caseback number has not been confirmed yet.
Credor (from the French "crête d'or," crest of gold) launched 1974 as Seiko's grouping of precious-metal "special watches," becoming Seiko's domestic luxury pinnacle — understated, ultra-thin, and artisanal. It set thinness records (the 1980 caliber 6720 quartz at 0.89mm; a revived mechanical 6870 at 1.98mm) and drew on Gérald Genta, whom Reijiro Hattori invited to train Seiko's designers in 1972 and who designed the Credor "Locomotive." The tri-crest logo first appeared on dials around 1980; Credor later produced Japan's first Spring Drive (1999), Sonnerie (2006), minute repeater (2011), and Seiko's first tourbillon (Fugaku, 2016).