A few years back when I picked up a few dings & scrapes on my Ruger GPNY .38spl revolver(stainless steel), a few gun forum members put out Mother's Mag Wheel Polish as a possible help.
A few forum members posted picks of wheelguns like GP100s Colt Pythons & Smith & Wesson N frames that were bright & shiney
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Mother's can be found in most auto care product stores like Discount Auto or Auto Zone.
Brasso or Flitz polish may work too. Flitz is a popular product that's been around for decades. Brasso is used a lot in the US Armed Forces for dress uniforms/Class As. Check the label to see if it works on stainless, ordinance grade steel.
For sales see:
www.brownells.com www.grafs.com www.uscav.com www.midwayusa.com .