One very tenus link could be that Alvis made armoured cars, Alvis ended up as part of BMC/British Leyland. BMC/British Leyland made the Mini, and the Mini killed the bubblecar.
Also, I think I'm right in thinking Ransomes had a hand with Hornsby in making "Mother", the first incarnation of what would become the WW1 tank. Ransomes, Sims & Jefferies I think later included Atco in their empire, and Atco of course made the Atco Trainer.
I also seem to think the Hunslet Engine Co. (They of Scootacars) may have had links with a War Department contract? It may have just been to supply locos but its possible a Hunslet engine may have been trialed in a tank of some sort....
Stuff for going on with anyway.