That's always been the knock on rubber grips. Since this one is Parked I don't know how much of an issue that would be. It might help to put some wax on the butt frame and on the insides of the grips.I kept a similar M10 ex-cop gun in the kitchen drawer. I decided to clean it one day after several years in the drawer, removed the rubbers and found slight rust starting. The revolver now wears magnas, great shooting gun.
Altamont smooth targets in walnut for $42
Pachs are great for shooting. That one isn't going to win any prizes with the "correctness" or "originality" crowd so why not shoot it as is?
I would like to suggest that regardless of the wood type that you select , rosewood is stunning , avoid any that say Laminate .I like these grips, I am thinking rosewood as opposed to the walnut - might integrate with the parkerized finish a little better.