Fred,
Perhaps not entirely the answer, but there are two entries for Lt Gerald J. Gebauer on
www.wwiimemorial.com First one says he completed 42 missions, the other 35 missions over Germany. He was from Detroit, Michigan.
Your date of 4th June 1944, was his plane lost that day? Apparently 467th BG didn't fly a mission that day.
Regards,
Leendert