Ah, another Lionel Hudson thread to peak my interests.
Superb work as always Pete.
For the record, the chassis' of the Lionel scale Hudsons was the same from the 1950 773 up to Gold Hudson of 2000, and I think a few others after. It was when Lionel brought out the J3a's and the later Vision 700E the frame was made completely different.
I'm doing something very similar (but significantly less intricate) with my Lionel Hudsons, so I'm looking forward to seeing how the control and sound electronics are going to go in.