[woodiewagon46]

The part you are trying to polish looks like a reproduction part. There are something like 26 or 28 grades of stainless steel ranging from S.S. used in knives and forks to almost non destructible jet engine parts. The more chromium in the part the better the shine. You don't know what S.S. was used in your part, nor do you know if it was annealed to allow the part to be formed. The pictures show a lot of "pitting" and scratches and just might be another case of "Chinese" junk. You may be "chasing your tail".