Tachy in crystal

I know there are some Omegas with these but this one is a LeJour that has a little crack in the crystal. The tachometer is retaining ring. What is the likelihood that I can replace the crystal and reuse retaining ring? Will probably be difficult to get a good fit. I haven’t pulled the crystal, but will do it to take measurements if it is a possibility. Something else about this watch: apparently it was made to commemorate Hans Herman’s 1970 LeMans win.

If you find the right replacement crystal part, I would say the chances are good that you can reuse the ring...