Minor scuffs and very light scratches can be removed using 3M or equivalent black, red or the common green scouring pads matching the "grain" of stainless steel.
"Frosted" portions that are worn smooth of stainless guns can be 'repaired' by taping the correct grit of abrasive sheets towards the steel surface and gently tapping the backing with a gunsmith's mallet uniformly to match the bead blasted surface.
