The newest MTH Madison sets appear to now have new style HO size figures in them. Do your cars have the older figures inside? If not, what size?
BobbyD - I used Bachmann O Scale figures as my main reference. Interestingly, the MTH heads on the passenger figures seem scale but, as you transverse downward, the limbs, trunk, and legs (if they have legs) seem to get smaller in scale. This is fairly apparent in the leg height. I assume this is done purposely for the standing figures so they can be seen looking out the windows. All of this makes me suspicious that the height of the MTH passenger cars is not truly scale, mainly in the lower portion, to accommodate the high rail wheels. That is to say, from ground level the passenger cars are scale height, but if you were to measure the height of the frame alone, it would be less than the "prototype" measurement.
The tables in the dining car seem very short height wise from a visual perspective but the MTH 20-64xxx interiors are such a pain to access that I dare not try to measure this. (A few of them have loose figures in them. They can't be accessed via the side doors or the ends so I let them stay dislodged.)
Those modelers who strip the interiors out and replace them almost always replace the figures anyway or move the existing figures inwards. There are so few to begin with.
Anthony