I've got a 1991 Kart World catalog that has that mini vette listed in it, made by Manco. I think the catalog I have lists it as a 3-hp Briggs motor. They also had an Indy Car style one at that time, too.
Way back in the mid '80s, the first Kart World catalog I had (still looking for a copy circa 1984 or 1985, if anyone has one!) had a ton of mini cars available, ranging from vans to indy cars to corvettes and more. Not sure if those were also Manco, just remember a really long list of body styles available.