Very interesting! Assume the cab is in the front and close-set wheels are inside the bottom part, or solid-rubber wheels (or "artillery" style metal wheels) on the outside. Hard to believe it could cross the moonscape beaten zone, though, with an engine that would fit anywhere inside, and high ground pressure. Might have been useful, however, if one or two could be towed behind "Mother" or one of the rhomboid tanks.
(Or might this have been cover and deception for the actual RN tank program?)