Well, sort of. There is no doubt the M50 was a strange looking beast. The US Marines were the only force to employ the M50 operationally, and it had some success as a fire support vehicle, and was generally well liked by it's crews, but it had a number of fairly serious shortcomings including very thin armor, a high profile, and the need for the crew to exit the vehicle to reload the gun tubes, which was extremely dangerous in a place like Vietnam where snipers were a constant threat. In the right situations Ontos could be formidable anti personnel weapon against troops in the open, as a "bunker buster", and for reducing barricaded positions, machine gun nests etc., but as an anti tank platform (it's original designed purpose) it was essentially a failure, although in Nam' this was of little consequence since there were few if any tanks to shoot at. Aside from the relatively few Marines who crewed the M50's, most people who served in Vietnam have never even heard of the thing. Might make an unusual subject for a custom though.