Like I said in my original post I've already replaced the stock with a syn one. This being a truck gun here in Texas means it's been exposed to extreme heat from being stored inside a locked up truck with the sun beating down on it repeatedly, 130F+ temps.
I have the West system epoxy with fast and slow set hardner, left over from my boat repair. I also have most of the fillers for it too.
Ain't Gunny the survivor? Sending you messages even though the Apocalypse hit! His advice is excellent, the real question, how much time do you want to spend on this stock as the number of times you will have to inlet, wait for glue to cure, remove action, then inlet, wait for glue to cure, remove action, etc, etc.
If you use thick enough epoxy layers, you can create a "cradle" for the action. This is more or less what I did for a Rem M700
First, created Bisonite pillars to keep the action true.
then routed out a god awful amount of wood with a Dremel tool
Given long drill bits, a two part epoxy that flows like honey, which Bisonite does, you can hollow out a pistol grip from the inside and pour epoxy down the hole, and let cure. But, this assumes the wood on the outside still does not shatter.
Marine stores have some of the best two part epoxies around. Used to haunt the ones around Port Clinton during down periods at the National Matches. I have used a lot of Marine Tex. Devcon makes incredibly hard steel, aluminum, titanium filled two part epoxies, and the Devcon I have used has a peanut butter consistency for the first 20 minutes. Once it hardens, you have to grind it out! The only real downside, is the cost! Bisonite was popular with the Garand and M1a gunsmiths, it poured into the side channels and then, it got thicker, and was still usable a little after that. I think Bisonite was steel filled. It cures glass hard.