Stainless has no coating. File or sand with what ever grit needed to remove the flaws. Sand in opposite direction with each finer grit to make sure scratches are gone. Use heavier grit in damaged areas only to eliminate extra work. Finish with 1500 and polish. Aluminum is anodized which can be removed with lye or sanded off. Same procedure only finish with 800 grit. It is not necessary to re-anodize. Here's my results.
Doug