Since you asked . . .
I took a gun refinishing class some years ago, and took my grandfather's rifle with me as a possible project. This is the rifle he taught me to shoot with, and left to me when he died. It looks like it spend its life outdoors, sun bleached lighter on the right side from lying bolt-handle up on the package shelf of a Ford coupe. The teacher persuaded me to leave it alone, because it wouldn't remind me of my grandfather if I made it look new. So, I left it as is and take it hunting a few times a year.
If your friend had hunted that gun, especially with you, I would have to vote to leave it alone. Since he didn't like it the way it is either, I see no reason not to make it the way you want it.