On the left, the Grand Seiko 6145-8000, and on the right, the 6146-8000. Both early variants distinguished by the “Grand Seiko” text printed on the dials. Except for the VFA’s, these were the last Grand Seikos to actually mention the brand in full on the dial until the quartz models launched in 1988. All subsequent 61GS, 45GS, and 56GS only featured the “GS” logo on the dial.
The 6146 is from the very first month of production, October 1967. The 6145 from January 1968.