On June 18th 1996 we were visited by a freelance writer, Bernard Towler, who mentioned that he had an interest in stamp collecting.
By way of conversation I mentioned that I knew a man called Adam Black who had married a girl whose first name was Penny.
In the 1980s an ad had appeared in a national newspaper for a stamp collecting convention in London and asking for people with such names to attend. She had gone along, and... two other Penny Blacks showed up too!
Bernard responded that he had written an unpublished novel called Stamp Lover in which the central character was called Black.
At the end he decides to call his daughter Penny.