You need special dished bolts, I found them on ebay. The originals are about $100-200 for a full set, the other chrome ones were about $45. I tried to clean them with a special wheel rubbing compound, which cleaned them nicely but did not do anything to the actual shine of the wheels as they look to have a clear coat on them. To polish, I expect you'd have to strip that finish off and go from there!
Good luck
B