To me an old rifle can be allowed to wear it's patina of history with a bit of pride, wire wool/wire brush anything loose & wipe it over with an oily rag, is fine.
If lots of the surface is through to the silver of the metal, cold blue can look OK as a finish without trying to hide the age too much.
But mostly it's personal taste, I'd take a stock sprayed olive drab over one waxed & polished any day, nothing on a gun should ever shinebut others will disagree.