Hi Frank
Marcel and Berta always claimed to be swiss, he was actually born in that border country. And he did fly gliders in the olympics, but a lesser known item is he also flew aerobatics for the germans in one of the intrernational contests right before the war. I asked them one time about whether he flew in the war. He got real quiet and just smiled. I think he did. All I know was he was a madterful glider driver and taught this kid alot.