I can't fine a SS number for him and he probably never applied for one - didn't need it. Yes, he did come to US during war. Germans occupied his home and sold everything, but lucky for him, when he returned, he was able to buy it all back (apparently the locals all had it is the story I've been told.) When my father was stationed in france & germany in 1945 immediately after the war he did go visit
Uncle Forsythe and the home looked like he'd never left it. I don't know if he kept his passport up to date (renewed) when he kept traveling or not. It does expire after a period.
Jean