Those old Weaver or Atlas 2 rail models are perfect as the whole China drive motor drops right into the Lionel frame and the wheels are already insulated plus there is a pickup on the insulated side. I have 2 of these in my collection that are basically for parts. By taking the motor and drive train out, placing them on the Lionel frame and soldering the pickup wires correctly, I have a lovely 2 rail Lionel diesel with Legacy. I know others have insulated the Lionel wheels and have had mixed results but the old swaparoo is tried and true as long as you have a donor. Because Weaver is now in the dust bin of history, getting the 2 rail China drive units may be a little difficult. Atlas still uses them though so I may investigate their availability if I move forward in buying one of the new Lionel geeps or sharks. Thanks all, I forgot Flyer was using Legacy these days. Sounds like I am in business. I will post photos when all is complete and I have not blown up the train room.