Chris,
I believe the answer to your question is that the ONLY differences between AM and SHS/MTH/Scale Trains hi-rail vs scale cars are the wheelsets and the couplers.? ?The 'bodies' of the cars are identical with same level of detail.? ?Both these manufacturers also have Kadee mounting pads molded into their car body so once the trucks are removed to remove the AF-compatible coupler, installing a Kadee or equivalent is easy.? Then, its a simple matter to swap out the hi-rail wheelsets for scale ones.? ?One of the things that is often not understood by those new to S from other scales is that AM and SHS/MTH/Scale Trains both use the same sprung truck side frames for for both scale and hi-rail wheels.? ?So if you buy a hi-rail car, you really don't need to replace the complete trucks...only the wheelsets.?
The attached is from a presentation I've given to NMRA meetings explaining the challenges and opportunities of modeling in S.? It shows a 'hi-rail' car in the foreground and the Kadee pad is visible in the car in the back.? The hi-rail wheels are easily 'popped out' of the truck and the scale wheels installed.
'Hope that's helpful!
Brooks
