Mr Stuart, a theatrical mask-maker and scenic artist, founded Mechanimals at his Bluegate Studio in Thaxted in the early 1950s after watching donkeys taking children for rides at the seaside.
He set about making petrol-driven pachyderms, modelled on Asiatic elephants, each capable of taking up to 12 passengers for pleasure rides in a howdah, an elephant carriage.
He thought although it was cheaper to buy a real elephant, feeding and stable costs would be much greater than the cost of petrol, making his creations a bargain for seaside and theme park operators. He was not happy with the initial stiff-legged elephants as they were not realistic enough, so his employee Maurice Radburn came up with a working, walking model.
An eight-foot-tall and 12-foot-wide elephant was then constructed.