Hey Robert.
While I don't have any RAGING BULL cards, I have seen some differences in other card sets that have raised my suspicions.
A few years ago, I picked up some lobbies from THE EXORCIST and I noticed that while the cards looked identical, one had the copyright date and the other did not.
I passed on the ones missing the date, assuming they were either reprints or counterfeits. They were quite 'minty' to boot and seemed stiffer/thicker than originals I already had.
Personally, I haven't seen much info regarding lobby card bootlegs. I'm sure someone on this board can add some info to this thread.
Do you have any pics you can post?