I agree with the others - try denatured alcohol (shellac thinner) first. You might be able to save the finish underneath after all. I forgot about finding any due to the COVID.
If that doesn't work, I'd probably call this a mystery finish. If he's still around, you might call the "pro" and ask what he used, then go from there. If it remains a mystery, I'd be awfully tempted to just hit it with the nasty spray stripper (get all the metal off of it that you can 1st). I've never tried it on really nice wood, but it didn't seem to hurt the old military walnut, birch, and coachwood stocks I've stripped, many of which had been subjected to rattle-can paint jobs over their original oil or shellac finishes before I got them cheap. It pulled the rattle-can off as well as the original finish.