2 weeks ago a friend of mine gave me a vintage omega seamaster deville date and I started noticing differences with other omegas such as a non omega logo crown, a simple back case with no engraving and the gold is peeled off in some areas. Why is this?
Please help

 

I don't think it's fake. However you are correct in that very little on the watch is original. The crown is indeed a generic replacement and so is the caseback. Not sure about the dial either... looks like it may have been repainted at some point? The Swiss Made text looks off. Can't see the movement so that could be incorrect also, but there's no way of knowing unless you remove the caseback.

Happy to be corrected of course!

 

At the very least it's a redial with an incorrect crown and second hand. The case is gold capped and the gold is wearing off. Swiss Made should be below the markers but it doesn't look like there's enough space for it to be there. The dial might belong on another watch all together which would make this a Franken. The marker to the right of the date looks odd compared to the rest of the dial.

 

Actually this would be a gold plated, probably 20 microns, case with stainless steel back.

Probably wasn't a Seamaster before the dial was refinished, case is not correct for a SM DE VILLE either, snap back and different overall design.