You may be able to find a donor watch and use its dial, or you can work with a watchmaker who has an Omega parts account to see if service dials are available. Same for genuine Omega crystals, though I think generic crystals that fit are readily available.
More to the point, though:
1. What makes you think the dial is the same as your original dial, only repainted? I.e. why are you sure the current dial isn't a replacement (perhaps a poorly painted replacement)?
2. What's wrong with the crystal?