Cannot offer any real help but there is a small point which could be important. You say the 1940 census says that George, age 36, was born in Yugoslavia. Quite impossible - Yugoslavia did not exist then. He was probably born somewhere in the Balkan Austro-Hungarian Empire - Croatia, Serbia, Slovenia which came to an end c. 1919. Suggest you Google up Austro-Hungarian Empire which would give you an idea off the size and variety of the nationalities living there. A very important point could be if you know the Language he spoke at home and also his religious denomination. Good luck.