I can neither confirm or deny the existence of this „book game“ to be in my possession, or then again not in my possession. The administration does not offer any comment on rumour or conjecture, nor does it use Signal messaging app for important communications. That said, the U2 spy plane is as an iconic piece of Cold War spy-craft technology and is still being used today (see below, another information packed book game from Historic Wings, to join my growing collection): 

Geordie’s Big Battles