I assume none are Omega as they all appear to be male on the crown, and all the split stems I've seen with Omega have been female on the crown.
Thanks again everyone! Regarding functionality of the male stem, I have a few other omega female stem/crown combos lying around and I tried some on the De Ville. One in particular worked very well and I would've kept it on had it been gold tone instead of steel. Will keep my eyes out for hands I guess, no rush at this point. Will report back on whether the new stem/crown combo work, cheers!
Indeed! Needs a little bit of aging to really match the rest of the watch, but oh well. Also still on the lookout for the minute hand! Thanks gents.