Grand Seiko 6146-8010.
The 6146-8010 doesn’t turn up very often. It can be easily distinguished by the graphic on the dial around and under the GS logo, often referred to as ‘Arabesque’. Though thought to be a precursor to the 615x “Special” watches, whose movements were regulated to +/-3 seconds per day, this particular example is from February 1971 – fully six months after my earliest Special.
Any contemporary documentation on this watch would be most appreciated!
This one is unique amongst all that I have seen in that it has an factory original custom engraved caseback. As per the engraved dedication, the watch was produced for the 60th anniversary of the Idemitsu company. No other engraving appears on the outside caseback around the gold GS medallion. The model number and serial number both appear on the inside of the caseback.
A most intriguing watch!