We don't need to put our watches in alcohol but I am really looking forward to your result. As i said before, it wouldn't be strange if a watch comes in contact with alcohol. I mean, when you're in a crowded place, holding a drink in your left hand and somebody accidently bumps into you ... Sorry but alcohol is a product we handle to often, a watch should be resistant to it
Yes, finding a new buckle won't be the problem.
A saphire caseback like you proposed might be good, but who will guarantee that the problem will only stick the caseback, what if the case will be affected too within a few months or 2 years ?
BTW, in the last 5 days I saw 2 339 with a caseback which have a white shine, not the original brown anymore. And these 2 were not internet pictures but I had these 2 in my hands. I happen to know quite a few people who collect watches and 2 of them have a 339. So don't tell me this is an isolated case.
On the other hand, I wouldn't be afraid. If I would have a 339 I would keep it !!!!!! It is a wonderfull watch and one way or the other Panerai will bring a solution