I have written before about the importance of a functioning crown over having an original one. I get asked all the time "Can I keep the original crown on the watch?" Sure, if you want the watch to look like one of these.
These are several examples where owners wanted to keep the "original" Omega crown. I deal with this more than I would like to. An "original crown" has ZERO value to a watch if the gasket inside is no good. How well would you expect a rubber gasket to hold up after 50 or 60 years? I would rather have an aftermarket or another brand crown than a bad original. Every watch I buy gets a new crown if it needs it. If the original brand is not available, use any other brand till you can find one.