IMO dial is original. See image from
@Franco's website. No register marks on the subdial.
View attachment 613859
http://squelettewatches.com/chronometres-30mm/
Crown looks to be an original Omega, although it could be a replacement on this particular watch.
My guess is that the owner(s) were heavy smokers. Can't be radiation damage as there is no radium on the dial.
Good luck with the project.
gatorcpa
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