There's just been a documentary on TV about a Walter Thompson, a Special Branch detective who was Winston Churchill's bodyguard from the 1920s and throughout WWII. Their association went back to 1914, when Thompson was temporarily attached to Churchill while his regular bodyguard was on holiday.
Amazingly, it was during this short period that Churchill attended a demonstration on Horse Guards Parade, and Thompson was with him. This can only be the inspection of the One-Ton Pedrail. In his memoirs Thompson claims that Churchill observed "some machines on caterpillar tracks" and said, "We can put a gun on that."
The documentary admits that this is a very simplified account of what went on, and, unfortunately, illustrates the episode with some stills of the Killen-Strait (with Stern aboard) and the famous artist's impression of De Mole's design, both of which are, of course, entirely inappropriate. But he was there.
(He also, while an ordinary policeman, happened to be standing near Churchill at the Siege of Sidney Street in 1911 when a bullet fired by one of the Latvian anarchists went through Churchill's top hat. I never knew that. A couple of inches lower and it would all have been very different.)
