2652 is a screwback, the bezel looks thin, so it looks like it could be a 2648 to me.
Yeah, the 2652-suggestion was stupid, obviously. 😁
But Constellation and Waterproof on the case back of a 2648, is that a thing? Genuine question, my example and 2-or-so handful of others I've seen didn't have those two words.
Unusual to have lumed hands but a no-lume dial.
The place selling is reputable, they say they won’t open it because they lack equipment to close a snap on water resistant case. Most likely they don’t want to risk damage to a customer’s watch.
Yeah, the 2652-suggestion was stupid, obviously. 
But Constellation and Waterproof on the case back of a 2648, is that a thing? Genuine question, my example and 2-or-so handful of others I've seen didn't have those two words.
The back is great, the observatory and the stars and the writing at the top and bottom are crisp, but the dial looks redone to me. The crosshairs don't seem to align with the star or the omega logo and they cut across the numbers which isn't right, I think they are supposed to stop before the numbers. It also looks too white. If the pic wasn't so blurry you could probably make out printing issues as well
