https://www.ebay.com/itm/working-OM...pid=5338899135&customid=&toolid=10001&mkevt=1
This late 1950s Seamaster - my guess would be ref. 2846 - looks like it might be pretty nice. Gold-capped case that's definitely seen some life, has a couple nicks here and there but doesn't look too polished. Sharp, large hippocampus is a nice bonus and personally, I find those two-tone dials to be a stunning configuration. I'm guessing the little flaws wont really show on the wrist, while the nice dial will. Crown is an incorrect replacement, but not a bad one (and will certainly be more usable than those clover crowns, which, should you wish, can be found on eBay pretty easily).
No movement pictures, of course, so factor in a service, even though seller says it's running well. And be quick: It ends in 90 minutes.