A lot depends on what the blemishes consist of. Are they holster wear marks? Is the nickel plating chipped? I'd suggest you clean it first & see how it looks before deciding what the next step will be.
I clean my series 70 satin nickel combat commander with breakfree CLP & it looks as good as new. Mine has the rampant Colt wood grips.
You might consider contacting Colt Mfg., Cylinder & Slide or Richard Heinie for advice before doing anything to it that could decrease the value of your firearm.
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