Comments:
... SM600 remains of collection interest. SM600 with Cal. 601 is a perfect match, manual winding, three hands, medium size and 2 adjusted positions etc are just sufficient elements to be claimed as a reliable and classic movement.
your one is one of many variants of dial, but please beware of a lot of refinished dial for sales out there.
congrats, Thomas,
stefan
My seamaster 600 (of course from 1964, Graham)
The latest purchase. I has a little patina on the dail, otherwise in good shape. I would have preferred a 1967 but had to do with a 1964 
Ref. no: 135.0012
Movement: 21515XXX
Cal. 601
Year: 1964
Best
Thomas
very nice Thomas, a classic time only watch IMO
they come in a decent size case unlike a lot of other brands during that era, they look classically simple, there are a vast range of dial variations to please everyone. in short an sm600 is a great vintage purchase.
i'm not at all jealous as i have 2 from the same year. a 601 and a 613 with date
just wait until Stefan reads this as he has about 10 million of them
enjoy it Thomas as winding it will give you hours of enjoyment over the next 30 years.
best
Graham
glad to see another folk who likes SM600...
... SM600 remains of collection interest. SM600 with Cal. 601 is a perfect match, manual winding, three hands, medium size and 2 adjusted positions etc are just sufficient elements to be claimed as a reliable and classic movement.
your one is one of many variants of dial, but please beware of a lot of refinished dial for sales out there.
congrats, Thomas,
stefan