I have seen this on more than one occasion and after talking to some "old timers" I have learned that many law enforcement agencies used to recommend this: Inscribing your name and/or Social Security number on your firearm.
Of course now a days we fight to keep our Social Security number out of thieves hands as our identity is far more valuable to thieves than any gun.
There is some irony here in that the Social Security Administration would not give out the names and addresses of a Social Security account to anyone, including Law Enforcement (although that may have changed). I have read numerous stories of Police Department evidence lockers full of guns with SS numbers inscribed, but no way to find the owners.
My gun-dealer friend asked me if I could polish and re-blue a model 94 Winchester rifle that he took in on trade.
If you know anything about the model 94 (or have read my blog post on them) you would know that some of them cannot be blued using conventional methods.
As luck would have it this gun was one of those made with a "sintered metal" receiver. The rifle, made in 1978, was just a few years too old (they switched back to forged carbon steel in the early 1980's).
As you can see from the pictures below, the gun is in immaculate condition. The only blemish is the Social Security number inscribed on the side of the receiver with an electric pencil.
Sanding the metal down smooth would most assuredly remove the iron plating and render the receiver un-blue-able (is that a word?).
So how on God's green Earth to I remove the blight and maintain the original blueing?
Here is the gun as it was brought to me:
Here you can see the SS# inscribed on the receiver (I removed the last 4 numbers digitally...too bad gunsmithing isn't that easy!)
I was forced to concede that there is nothing I could do for this gun....short of finding a shop that could iron plate the receiver before I blue it.
Not all guns can be pretty, some are just destined to be tools.