I've decided to get a vintage Omega instead of spending 500-700 on a new watch. I looked around on eBay and I can grab one for ~$300. Awesome!
Now the questions. I found an auction with the case number 166.121. I definitely don't want to wear a watch around that has a cracked crystal. I did a little search, and it's not listed in ofrei.com under crystals. ofrei.com does have the case number's bracelets, though.
So... What do I do when this happens? My google-fu isn't strong enough to find an aftermarket case to fit the vintage, since a search with the case number pulls up nil.