“One brainwave my father was proud of was the plastic explosive shaped like horse or cow dung. He described with relish that when the German Army in Italy began to wake up to the deception, he had them re-moulded with a tyre track through them.”
Alistair Maskelyne

There is firm evidence from different sources that Jasper Maskelyne did indeed work for A Force’s escape and evasion wing. Maskelyne’s service record gives 19th November 1942 as the date of transfer to Advance HQ A Force in Cairo.
Maskelyne designed a range of escape items which resembled ordinary objects. He built a shoe-polish brush which contained a hidden escape kit. He developed a commando boot which secretly held a compass, a silk map and a special cutting instrument within the false heel. Diagrams of these devices, signed by Maskelyne and dated November 1942, appear in the 1983 edition of The War Magician. However, it is not clear if any of these ideas were taken up by the Army and placed into large scale production.
In the Archives, I came across a “Plan for concealment of escape devices in a battle-dress” signed by Jasper Maskelyne in July 1943. Click on the drawing to find out how his escape & evasion work ties in with other inventors.