I was in the
navy, on the bridge, on ships mostly built in WWII. They had lots of brass. We used Nevr-Dull. A cotton wadding impregnated with brass cleaner. After doing many hours polishing brass panel covers we came up with coating the polished brass with a clear plastic coating after removing the polish residue with acetone. We never had to polish that brass again. The coating was varathane in a spray can.