Well, if you want to keep the dial etc as-is, the only real difficulty I see is the bezel insert, for which, realistically, you’ll need a repro part. It’ll never be in a “collector-grade” condition anyway, so why not (and I dislike the term, but I hope everyone knows how it’s meant).
For the movement: 501s were produced in millions, one of the (if not
the) easiest 50s Omega movement to come by. Buy a good example, shouldn’t set you back more than 200$. Have a watchmaker who’s into vintage watches replace it and, importantly,
keep the serial of your watch. There might be some smaller issues to take care of, rust at the stem / hands etc but that shouldn’t be an insurmountable object.
Would love to see the final result.
😀