Dave Lovell spotted these crafty pencils with escape route maps inserted into the pencil barrel from WW2
“I was particularly interested in the Maps for POWs secreted inside pencils. I wonder whether this cunning plan, expertly implemented led to any successful escapes. Maps were essential to the war effort on all sides of the conflict. http://www.escape-maps.com/ and https://www.bl.uk/maps/articles/escape-and-evasion-maps-of-world-war-ii“
