Old grime has to come off and sometimes we just have to get inventive. Shellac can handle a damp cloth, but it can't leave any dampness on the machine. These days many of us have polishe up the black machines with resin based car polish, even dull machines shine up impressively, it lifts up grime and dirt even after a good cleaning. If it's in very good condition it should clean up easily.
Last edited by Mickey2; 11-24-2018 at 09:47 AM.