Mirror polishing of small internal lock parts n days past was a profession and a skill that is hardly done today. The only trade where it is still done regularly is in high quality mechanical watch and clock making. Some of the older products used are still available but at a cost. Abrasive stones are just one of many abrasives though the problem is what type is used for finishing "Water of Ayr" stones are available in many grades for producing a high finish on hardened steels the finest polish is obtained with Dimond dust in olive oil, Jewellers Rouge in
any oil. To bring the metal surface up to a level where you can consider working it to a mirror finish the following items are of a great help "Engineers Emery sticks" of various shapes and abrasive sizes, mechanical buffing wheels using various paste polishes "Tripoli" polishing soap is a good all rounder to get a high polish on softer metals though using polishing wheels does have a tendency yo remove sharp edges killing that sharp overall effect. Dont forget to use finger protection when using mechanical polishers it will be a painful lesson if you dont.
