Mark 4 No 1 serial number recovery

[Rick]

My brief stint in the cop biz before deciding jumping out of airplanes was more fun is about 40 years in the past. But I remember watching the ident guys using some kind of mild acid/caustic to raise serial numbers on stolen stuff where the serial number had been removed by thieves ie with a file. It was pretty amazing watching the serial number appear in the middle of the tool marks from the file or whatever. It was pretty mild stuff, whatever it was, because you didn't see anything happening on the exposed surface, other than the stamped numbers and markings starting to appear.

But I don't know whether acid or caustic, what it was, or what the strength was.

If you've got friends in the local cop shops, you could ask them if there's local ident members, and if so, were they open to helping you with your hobby.