I have most of those details. As you may recall I am writing a biography of Kupfer. To date I have written about 172 pages of text and have 140 photographs (about half are original in my collection). In addition to the published information on him in a number of contemporary magazines (Der Adler, Die Wehrmacht, and Signal) and in his file from the Bundes Archiv in Freiberg (mostly post mortem material regarding his veterans benefits for his parents), I have 55 personal letters that he wrote to Walter Ludwig (the tenor) and his wife that give an interesting personal perspective. I have also been able to obtain his high school records, his bruschenschaft information from Heidelberg, and as you know his Ph.D. dissertation from Erlangen. The areas where I need additional information include his time in the Freikorps in the early 1920s. He participated in putting down the communist uprising in Thuringia (possibly with the Viking Bund). His time in the 17th Bavarian Cavalry Regiment between 1928-1938 where he won the life savings medal (I would love to know details about this). Documents and details on his divorce on Feb 19, 1942 in Munich. Information on his son Ernstel who moved to Dresden with his ex-wife who had remarried and changed her name to Reisinger. They lived in an area of Dresden that was totally destroyed by the fire bombing in 1945. Were they casualties or did they survive the war and is his son still alive. His brother Hans was reported missing in Stalingrad and presumed dead, but I haven't been able to confirm this. I need to locate the sister of his friend Gunther Schmid who was killed in 1943. She lived in Stuttgart. She may have some photos of him and Gunther. Finally, I have corresponded with 4 surviving members of St.G.2. Only 2 have replied, but they have been able to give little information as they were generally not based at the same airfields as he was. 2 did not respond.
Do you know anyone in the Munich area, that is honest, and that I could contract with to search some of the archives and track down some information on the above outstanding issues. With a good dictionary I can read German, but do not write or speak it.
Thanks again for your interest and information.