Bill... the question isn't if Jr. has the last name Lugosi but where did the middle name George come from if he is a Jr. and his father doesn't have a middle name George?

Maybe he did like the Chaney's did - sorta? Lon Chaney Sr. vs Lon Chaney Jr. In this case Jr. is not so. They have two completely different legal names (Sr. is Leonidas Frank Chaney and Jr. is Creighton Tull Chaney). In this case the movie studio decided to change Creighton's screen name to Lon Chaney Jr. to cash in on a link with his father's fame.

Eric