AMI C!!
I did fix this jukebox (last June) and it was swelled up pot metal barrel jammed in the rotator/pickup mechanism, (piston) where it grips the record by carefully supporting this rotator and carefully beat on with wooden mallet to get this to extend out. This allowed me to free this gripper up with careful filing round the barrel. Then restored the mechanism by putting gears in correct relationship as it was attempted to be tinkered with because owner wanted to able to play the records at the events especially with that poor little motor still humming in jam.
Trouble 2 was tarnished contacts in the "logic" relay (behind the swing out panel for the coin mechanism) and one loose solder joint. This improved much that quits constant cycling of records in and out. hehe.
I hope boss or coworker had told the owner of this jukebox who have vintage stuff in the funhouse (hosts dances/big events) to do proper restoration on this one.
Cheers, Wizard