A large oil painting of his close deceased comrade Endrass hung in his home after the war up until the time of his death. In his front room overlooking the Rhine River was the top of the periscope from U-552, which immediately after the war some of his crewman had managed to remove from the captured boat and pass to him as a keepsake. Topp died on 26 December 2005, in Süßen at the age of 91; he was survived by two sons, Peter Kay (1945-2015) and Michael (b. 1950), and five grandchildren.