I've been down this road before......
The other year I made a deal with another of my club's members and part of the deal was another M1 Garand (and a few bucks, not unreasonable) and rather nice for the total cost. After shooting it and having minor issues with it feeding the first round twice (which may be due to the stock being sanded several times and the fact that it takes little pressure to snap the trigger assembly into place, yet it shot and functioned just fine after the first round if which the charging handle was struck smartly) I decided to try another stock from the CMP. I'm still a'waiting it's delivery.
My choices were to either glass bed part of the action and trigger assembly or try another stock. In my view to glass bed I'd need to first route out a channel underneath the action (not hard for me) and bed that. Allowing just a tad of pressure from the trigger assembly while it cured. Then do the same for the trigger assembly. Voila, tight bedding.
However, the stock was oiled originally. It was sanded with power tools (quite apparent) and then either shellacked or varnished. Or something else but I've not the desire to actually find out what finish is on that stock. The rifle is import marked (on the right side of the barrel just behind the gas cylinder), but from whom is up for grabs as the import marks are impossible to read. Maybe with computer scanning and the proper software it's possible, but I'm not going down that hole. And the stock is weeping oil under the action. So, to glass bed the stock I'd first need to bake out as much of that oil as possible and that would include a re-finish. Thus "changing it's history" and "offending" some. I'm not sure if the stock is birch or another light colored wood, but I'll bet money it's no kind of walnut.
So, it was a new stock or mess with the old stock. I'll be boxing up the "original" stock and using the CMP stock. And let's hope this does the trick.
When I said "down this road before" it was in the context that years ago a close friend gave me a Garand that was just being imported from Korea. It is an H&R and looked like it had been through the entire Korean War. But it shot just fine. But after awhile looking at that lumber which was supposed to be the stock (think of wrapping a rope around the muzzle and driving on a forest service road for an hour or so) I bought a Boyd's National Match stock for it. I was happy for a few months, then looked at the finish of the metal. Sent it off to Fulton Armory for gaging and re-parkerizing. Two replacement parts and it was as if brand new. However there are those that will cry about "damaging history." Maybe so. But I prefer working and meeting standards first. Let the history buff's argue about it after I'm gone.