There are so many of the things floating around in varying degrees of condition that I feel no guilt whatever over sporterizing the two I've done.
The least expensive one just got a new Boyds stock & a Smith adjustable front sight.
After which, it put three holes in under an inch at 100 yards with surplus ammunition.
That's despite the mediocre bore, and rust craters on the barrel exposed by removing the warped wood that came on it. Not speckles, craters.
Not every Mosin is a museum piece.
My more expensive project Mosin was re-stocked, barrel cut to 22 inches, rear sight removed, Duracoated, minor trigger job, and a Leupold scope mounted.
I coulda put that money into a plastic-stocked Ruger American or Savage rifle and had some left over, but I've got real wood & a rifle with more character that pleases me. It also shoots better than it did with its original furniture.
Making a run-of-the-mill Mosin into something that you can tailor to your own preferences kills no kittens & will not cause St. Peter to bar the gates when you show up.
A true collectible is a different matter, but I've about 8 go through my hands in the past 15 years or so, none fit that category.
Denis