The question is whether there is any overlap at all where the price would be high enough to motivate supply (worth it to him) but low enough that there's still demand (worth buying). Also factoring in the cost of marketing, since potential buyers don't just automatically find you.
There are a huge number of business ideas where there is no overlap at all. Finding an overlap even without competition is hard enough. (Then add competition and it gets even harder, of course.)
This is exceptionally cool to me. But it's not something you get to subtly show off in public, it's going to (hopefully) involve a cheap watch, and therefore the "timeless functionality" appeal is gone.
But seriously, it doesn't have to be displayed with subtlety. Somebody offer OP $10K for this so you can use it as a paperweight on your desk.
Let’s go really pie in the sky, maybe some billionaire sees this (surely there’s some hanging out on hacker news) imagine them giving OP a $30,000 pocket watch owned by Ulysses S Grant or something and asking them to take that one of a kind art piece and encase it in resin. What would the pay rate be for such a project? The sky’s the limit, really.
Hand made pieces that only an expert could assemble are extremely expensive.