Is there a way to touch-up small shiney, wear spots on brushed stainless steel? I'm talking about small areas, not an entire firearm. Thanks in advance.

Since there is basically (usually) no finish over the stainless (except Ruger) the trick is to match the grit which was used in the original polish. If you have a stainless kitchen sink, try so 400 grit wet/dry paper with some dish detergent and water to lube the process (on the sink) to visualize the finish gained. Make your strokes in the same direction as the original finish, and you will be pleased. Of course you may wish to do it with a wheel of some type with a brush...

A Scotch Brite pad works great! Green, wet.