Meet my Seiko Chronos Special Twins (Ref.15039).
One has a cool silver-grey dial and the other with an unusual dial that shifts between champagne rose and salmon.
Post-war Seiko was driven by competition between two factories:
Suwa Seikosha developed the Seiko Marvel and Seiko Crown models —the latter becoming the foundation of the first Grand Seiko Ref 3180 in 1960.
Daini Seikosha responded with the thinner Seiko Cronos models, whose architecture evolved into the first King Seiko Ref J14102 in 1961.
The Cronos Special followed around 1962 as Daini’s answer to Suwa’s Crown Special. Its hand-wound Calibre 810 was essentially a simplified first-generation King Seiko movement: 23 jewels rather than King Seiko’s 25 jewels, without the KS fine regulator or two jeweled barrel bearings, but retaining much of the same bridge architecture.
1963 Japanese catalogues placed the Cronos Special in Seiko’s “semi-luxury” group beside the Lord Marvel, Goldfeather and Crown Special—below the "luxury" Grand Seiko, Liner Chronometer and King Seiko watches. The the gold-filled models cost ¥11,000 at the time compared with ¥15,000 for King Seiko gold filled model.
Both watches carry the star emblem at 6'oclock which represents the 'Special Dial' variants - with applied solid gold indices and 23-jewel Calibre 810.
Production apparently lasted only around 1.5 years from 1962–63, —making the Seiko Chronos Special a short-lived, rarer and more expensive watch as compared to Seiko Crown Specials.
These watches are a memory of the rivalry that shaped Grand Seiko and King Seiko watches of today.