Hi Mike, on a quick search, not too much pops up on Joseph. The WWII Memorial website data just says he was in the Army & served in Europe. No results for an enlistment record at Nara website or on Ancestry.com. the only thing on him that comes up on Ancestry is a prisoner of war record, not much info to positively identify him as your Joseph but it could be.
World War II Prisoners of War, 1941-1946
Name: Joseph A Yurkonis
Race: White
Report Date: 15 Jun 1945
Latest Report Date: 13 Feb 1946
Grade: Private
Grade Notes: Cadet, USMA or Chief Warrant Officer or Private or Apprentice, Seaman
Service Branch: Army
Area Served: European Theatre
Detaining Country: Germany
Status: Returned to Military Control, Liberated or Repatriated
Report Source: Individual has been reported through sources considered official.