I sanded these grips on this gripframe to get a perfect fit,, finish with 800 grit and then with the grips off used the fine scotch bright pad and it looks like new, can't tell it from the rest of the gun in any way.
But NO the polish will make it look like a nickle finish, if its a deep scratch start with 320 and sand no more than necessary in the direction the brushed finish is in, the go to 600,, 800,, then scotch bright, I'd by a couple grits med, fine, extra fine, I have used the extra fine to polish 6mm PPC brass between relays in a match to keep em look'n puuurdy. always good to have a little of each on hand.