My understanding was, it was all his doing with no outside help. There are several videos of this item on YouTube. It is an extremely interesting piece of work. Nothing on it is short cut-ed the transmission, rear end, and other parts are copies from the way they are in a real car. Even if that is not true and I misinterpreted the process, it is fabulous for anyone to make. I just had to share it.
Dick
heppnerugy