Originally Posted by jplinville

800 grit to start, keeping it wet. Finish with 2000 grit automotive abrasive sponge, again keeping it wet. Grab a bottle of Mother's Mag polish and sit back in front of the television and rub it with a terry cloth polishing rag. Make sure to polish it all the same direction with each step up in grit...same with the Mother's. Semichrome works well, as does Fitz...but Mother's will do about the same for less money.

I've used this same technique to repair scratches on my Uncle's 686 in SS. His weren't super deep, so it only took about 6 hours by hand...don't cheat with a Dremel, as it will not be even.