84 + code-making

There's a terrific book called "Between Silk and Cyanide," by Leo Marks, that tells the story of how he developed the most significant British code-making techniques of WWII. Marks is the son of the owner of Marks & Co., and the book contains a few memories of growing up around the store. Marks also said that the pencil marks in the front of the books in the store that indicated price, etc. provided his earliest training in decyphering and creating codes. A fun adjunct to the 84CCR legend. It came out about 10 years ago--I can't say offhand if it's in print, but no fans of 84CCR should be afraid of a little out-of-print book search, right?