As the thread title asks, is there a Williams' engine model whose powered chasis/frame can be used to substitute for and work with one of their Budd RDC car model? I have a new Williams RDC shell that I originally planned to kit-bash into a diner, but now I'm wondering if I can locate a compatible Williams powered frame. I wondered if a Lionel RDC version would fit, but thought the items would not align properly. Meanwhile, I continue to keep my eye out for an inexpensive shell damaged Williams' RDC.
Any further information would be appreciated.