I am very grateful for your message! I have a partial family tree of the Hepner family, on which there is a Dr. Albert Hepner of Breslau, the son of Aron hepner, who would be of similar age to the Rabbi whom you have mentioned. Do you know of Hans Hepner (deceased) or Lothar Hepner who were the sons of Albert? Hans and Lothar also had a cousin in Haifa/Tel Aviv called Norbert Danziger (deceased). Any of these names mean anything to you?