I found your post very interesting, my Father's name was Johann Anton Brandl (born 30/06/1926) in Rosstal Bavaria, and his mothers name was Katharina Brandl, on his birth Certificate it says that she was a resident in Rosstal, but shows no Fathers name so I presume he was illigitimate, he talked about his Grandmother who's name was Freda who also lived in Rosstal he also talked about Ernst and Franz, I have been trying to trace this side of the family for some time now so I hope we have a conection.
Regards
Robert Brandl (UK