Well I finally managed to get my SM300 converted to the no date dial and Cal 552 movement. If I'd known at the time that the no-date dial was still available I'd have done it in the first instance. I am absolutely loving the classic symmetry and the fact that the lume on the hands and indices finally match. Please excuse the crappy cellphone pics.
Thanks. That's the great thing about these service parts watches. You can do these things without committing sacrilege