From what I can tell, this buggy isn't a Kyosho. The early Kyoshos had chain drive and were built on frame rails with a cylinder-shaped fuel tank that was rear mounted. The engine is most likely an OS .21 VF-BR, judging by the slide carb. The side of the block should have "OS MAX" casted into it. I'm stumped on who made this chassis. It isn't a Thunder Tiger Silver Fox. A good site to check out it http://www.landjump.net for info on these.

At any rate, what you have there is a nice piece of history...be nice to it.