Constellation - 168.017.

Hi, I've been looking at Seamasters and Constellations from around the mid-sixties to early seventies and was hoping for some guidance on a Constellation I've seen on eBay (can post a link if this would help).
It's a 'C' cased model - 168.017 with a cal. 564 which appears to be from 1972 based on it's serial number. What I'm unsure about is that I wasn't sure if 'C' cased Constellations would have been fitted with this movement in 1972, as I haven't previously seen any with this movement as late as this. The ones I've seen before have had cal. 1xxx movements. Also it has tritium lume, but the dial doesn't have the expected 't' either side of 'Swiss made'. Could the lume be a later addition, or the watch have a refurbished dial?
Thanks for any help you could offer.

I haven't studied the 70s models closely, but I think the lume plots on the OP watch are much larger than what they should be. And overall, they seem kind of sloppy. I would guess the dial has been re-lumed, and this would be a deal-breaker for me. With some patience, one can find a very nice 168.017 for a reasonable price.

Anything is possible with C-Case's, really hard to disprove things, rarities are more common than aftermarket modifications

Thanks for all the useful information, good to know.