So, I am sorting through my extensive assortment of future projects recently, and I happen upon a clear plastic covered container that looks interesting. Upon further examination, I find a complete Omega bumper type automatic (with calendar) that is all in pieces! No recollection where it came from! I put it all together, and voila! The result. I went through my stash again, hoping to find the case for it! No luck! I wonder if the case went to a scrapper!
I gather that the # 2757 is a style number? Since I don't have a case for it, I don't know how to answer your question. Such a shame, really. The movement is in fine condition, and the dial is pretty good for a 60 year old watch. I just Googled Omega style 2757, and lo and behold, there is one shown on line which appears to be that exact dial with (I surmise) the same movement shown. So style 2757 it is! I'd even be happy with a steel case for it.
That's a beaut! Hopefully, one day, I will be able to have one as nice, to show. When I Googled the Omega 2757, I came up with a Chinese outfit that sells a replica. I couldn't believe how good it looked! But I'll hold off until mine looks as good. Earlier, someone on this board commented about unequal distribution. It was tongue in cheek. While I was typing, pops up yet another nice Omega calendar! You're both unfair. You each have one, and I have only half of one!
Since I was not sure myself I just doubled checked, 2627 is the answer. Anyhow, I do like the curved window better though.