the front panel’s paint and decal were very matte, and had signs of yellowing outside the decal. Everyone who has dealt with a Royal 5 (in particular) might know a case of this illness: the paint appears dirty and uneven with some yellow, grainy stuff around the decals. You cannot clean over decals too much: the golden color will go away to reveal silver, and eventually you will destroy the decals completely.But I had heard that that yellow stuff, on some machines at least, was shellac: that the decals were originally applied and then shellacked. For some reason, on the Royal 5 in particular, the shellac had a tendency over time to dry and become apparent and grainy.

Use kerosene or mineral spirits to clean the machine. I wouod go with kerosene to be honest. Then redo the shellac finish with french polishing. This is heavy documented with old sewing machines as they use these gold decals that f becomes silvered when water or cleaning solvents touch them.