The TSA rules now prohibit special marking of firearms, for just the reason you cite - it was a "steal me" tag. I have flown with firearms, and it is OK, except that airline personell have no clue about guns, and sometimes ask for absurd things. The rules of the moment are at:
http://www.tsa.gov/travelers/airtrav...rial_1666.shtm
Keep in mind that the TSA rules have no relation to local rules. I knew a guy who was arrested in Boston for bringing a firearm to BOS from NH in violation of Boston laws. Happy travels.
H