Omega ST 145.012 was in production approximately from 1967 to 1969, a run of approximately 2 years, carrying the 321 manual chronograph caliber in a 42 mm case under a tachymeter bezel.
The last standard-production caliber 321 Speedmaster - and the reference Michael Collins wore aboard Apollo 11; sources split its introduction between 1967 and 1968.
Dates carry a "c." because that is what honesty requires: Seiko's own archive gives only approximate production windows by caliber, so the file states the documented range and marks it as such rather than inventing precision.
The full collector's file for this reference — variants, dial codes, and the authentication walk-through — is on the writing schedule; the specifications above are the permanent record.
Vintage Speedmaster fraud runs on the caliber 321 premium: later watches dressed with earlier dials and bezels, service dials passed as original, reproduction dot-over-ninety bezels, and relumed hands on trophy references. The movement serial is the anchor - it dates the watch on the Speedmaster's own sequence, and every visible part must belong to that era. Sub-reference engravings, case-maker marks and dial details all have documented histories; a watch is only as original as its least original part.
Production windows and specifications compiled from documented collector references and period catalogs, cross-checked across independent sources; manufacturer records for this era are approximate by Seiko's own account.