Eustace Maxwell died in the late 1960s or early 1970s, not late 1950s.  I last saw him in his flat in Buckingham Terrace in Edinburgh around that time - we sometimes met to play chess together.  His last years were spent attempting to perfect designs of car and bus washing machines (he was an early pioneer).  Edinburgh Council built one of them for its buses, but it suffered from unreliability.  He was posted for a time during WWII to Melville House near Cupar, near my father's family home.  I recall being told, truthfully or not, that he was involved in efforts to prepare for resistance to German forces if they invaded Scotland from Norway (a fear in 1940-41).  He became a frequent visitor to our own house in the 1950s when we lived in Invergowrie near Dundee, mainly because he was attracted to my mother.   It is correct that he loved driving fast cars - I remember a Porsche as well as those mentioned.  I and my sisters greatly enjoyed his visits.