[morzh]

John

Let's just say, I take a Qtip, wet it in either MS or IPA and really rub against the embossed letters. And it does not come out, though the Qtip comes out dirty every time.
The dirt is really compacted.
I think a real stiff toothbrush might do. And even then...

I would use a metal toothpick but I do not want to scratch backelite.
Actually, speaking of toothpicks, I have sharp wood ones, those that I used on knurled handles (after soaking in Goop overnight). Maybe those. Why haven't I tried them yet...probably got too much taken away by the scrubbing process.
"Shake it, shake it, don't think!"