Hello guys,
John: I checked Theo's NCA-book, but he only mentions the KTB I.Jagdkorps (which I also checked), it does not reveal the name of Bogensperger nor III./NJG 1. I will contact Theo to clarify this (and his) reference.
Martin: thank you for checking, I only had the ORB of 109 and 141 Squadron at hand
To be continued... Best regards, Marcel