Rich Grise wrote in news: snipped-for-privacy@example.net:
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.