Joe Pesci's character, Tommy Devito is wacked for killing a "made guy", Billy Batts after a arument about shoe shinning. The mafia requires all members to be clean shaven, but Billy Batts, played by Frank Vincent has a mustache...thats against the rules.
Have you not seen The Godfather part one??
A little fellow by the name of Vito Corleone, yeah him, that's a moustache you see on his top lip. Perhaps in the era of Goodfellas the rules are different, but regardless, what you've put forward is highly questionable.