A rifle or shotgun for that matter is only as good as it's barrel. Perhaps the barrel on the gun in question was junk. I love Parker shotguns and Pre64 M70's and while I have bought shotguns as parts guns I have never done it to a rifle. I have sunk money into a gun to bring it back to life. A case in point is a Pre 64 M70 7MM carbine I bought at an estate sale. I later find out that some idiot drilled a hole right through the chamber! The barrel was junk and rather than parting it out (I wanted an action for a custom project) I bought a Pre 64 barrel of a different caliber on E-Bay and now I have a hunting rifle albeit an expensive one.
I have restocked exactly one Pre 64 M70 a 270 FWT that the original stock looked like someone tried to free float the barrel using a chainsaw. This was 20+ years ago and in my youth I had a custom stock made for it. Now I'd like to find another FWT 270 to go with the rest of the FWT's just for the originality.
If your going to modify the gun keep the original parts with it. Just my thought. IMHO to take a perfectly useable gun and part it out is just plain wrong.