Some have suggested to me recently that British fashioned their Operation Mincemeat in WWII after details in the book “The Millner’s Hat Mystery” (by Sir Basil Thomson, published 1937).
Thomson (1861-1939) was a solicitor who had worked for British Intelligence and in the Foreign Service.
During WWI he served as an Assistant Commissioner to the Metropolitan Police.
Such credentials definitely give a detailed and grounded approach to his writing.
The story-line of this book, a seventh title out of eight books about a particular investigator, kicks off with a couple people who duck into a barn during a storm and find a dead man.
The death is reported as murder because of a fatal wound by gunshot without any sign of the weapon. However the victim’s identity is a total mystery, challenging the protagonist.
This search for meaning in a discovered body could have been a reference for some aspects of Mincemeat. However, the operation wouldn’t have worked if identification of the victim had not been intentionally made very easy (disinformation). That’s basically the opposite of a mystery.
Thus it seems more accurate to say the methods pioneered in WWI, such as the Haversack Ruse for Beersheba, had set an overall objective of disinformation that was used successfully in WWII Operation Mincemeat. If anything, the book could have been based on intelligence from WWI, just like Mincemeat.