You guys don't know how happy you made dad.
Since he has been having some health problems he hasn't been able to get out and do all the things he normally does. So this is something to keep his mind busy with.
He asked if the 17 looked like it was stamped before or after it was painted? And can you tell if the tag has primer under it or was it installed before primer? When the number was stamped would give an idea what it might be for.