I would email Henry and ask what kind of finish it is, then go from there. Your right, the wrong finish could react and make a mess.
If you have a heat gun and a couple of spare stock pieces you might want to try taking off the poly with the heat gun on one of the spares you ain't gonna use anyway. Using low heat, heat up a small area until you see it blister then scrape it off with a plastic putty knife. Don't get the knife next to the heat source cause it will melt. DO NOT IMO AND IME USE A PROPANE TORCH unless you gots lots of experience with em. Burns wood before you even notice.Well, if the original finish is a poly, then I see no reason not to just apply gloss coat of poly on top of that. There is no way I am going to strip the finish off the wood as that is just too much effort and nasty, caustic chemicals. I can always test whatever spray coating I get on another stock to be sure it doesn't attack the finish of this stock. I have several that Henry sent me when I was try to get some fancy wood.
Can you elaborate? How many did you end up with and what were they charging? I am thinking about a fancy stock set for my GB, but have not asked Henry how they pick one out(do they send pic's first) and what the cost might be.I have several that Henry sent me when I was try to get some fancy wood.