Actually there is very little market for old pianos regardless of condition (almost). Many are being chopped up for firewood (seriously).
You would think that something that old would be coveted by antique collectors but that’s hardly ever the case - unless it’s a classic Steinway or Yamaha grand. Upright pianos are least desirable. You literally cannot give them away.
My wife had a 1912 upright that her mother gave her. We lugged that thing from house to house for years. Always intended to fix it up but that when I did some research into it I found it outrageously expensive (like 10’s of thousands of $$ expensive) to have it restored. Finally gave it away for free to a nice kid on Craigslist who probably had no idea what he was getting into.
I thought about doing a mod like this as well but in the end just couldn’t make it happen. Glad to see a new life for such a gorgeous heirloom.
There’s probably a really good business model for someone with these kinds of skills.
