I know this thread is quite old but I wanted to chime in with my experience. I took denatured alcohol to the head of a 201 without minding the decals at all. My pad was soaked with the stuff. It immediately turned my gold decals to silver! I couldn't believe what I was seeing. I obviously didn't know what I was doing and I thought the denatured alcohol would do no harm! Oops! It is fine, I just have an original Singer 201 with silver decals. Live and learn, as they say!