I've used white spirit, a metal halide lamp, and the lens from an old Zent
35mm camera as a high powered magnifier. I got most of the IC numbers from
a LambdaPro laser PSU, and LambdaPro grind them off to hide them. If
they've only been rubbed enough to obscure them a bit, this should work on
them. Try with different light and viewing angles.

What's "American" for white spirit?

I'm willing to try...