Lots of finish/paint removers that work. What I don't like about it is that it's put it on, remove the sludgy melted finish that does come off, repeat until all off. Messy and very hard to keep that mix from getting down into the bare wood.
If you're up to it, look into what I would call flat blade paint or finish removal. It's an old time way that they used to strip piano finishes off to re-do them. Basically using a sharp square edged tool that you just tilt at an angle to scrape the finish off.
I did a M70 that way and liked the outcome. Little tedious but not that difficult. Once I had all the finish off to the bare wood, I did the whole wet sanding process to fill in the open pore's and applied several coats of finish. I did tape off the stock and remove the finish in the checkering areas with finish remover.
