It's so long ago since I last did any I don't recall what I used to remove the sticky stuff, probably WD40, which seems to shift most self adhesives, with a little patience.
I removed them long ago, this seems like one of those things that's always overlooked. To my knowledge there was nothing important on them aside from the VIN but that's stamped into the neck.
I got real angry and took out a knife and... You know those warning labels on motorcycles, I cut one of them off. I've got a bad temper Peewee. That's why I was in jail. I'm bad, really bad.