Black Magic Holiday is online for free and I stumbled across the spanking image through a normal random search. My belief is that Harold McCauley is the illustrator. There were two illustrators in the book and the image seems more in line with McCauley’s work. Obviously I won’t bore you to tears with any in depth analysis, if you need anymore info then you have all of the tools now to search for the book.

Of course this was back in the 1950s when the largest person in the room always got called “Tubby”.