I may have found something. While researching Mini information for another puzzle, I came across a blog with this exact picture in it. It is a child's pedal car made from the bits of a couple of bicycles, and plywood. The picture caption doesn't give the builder's full name, but refers to him only as: Terry. However, the name at the top of the blog (which contains information on several homebuilt projects) is Terry Lyttle. I'll guess that the builder and the blogger might be the same person, and suggest that the name of the builder of the puzzle car might be: Terry Lyttle.