Charlie,
56 seater railcar, can't say I've ever heard of them pulling a freightcar/trailer but they were used in pairs: see the last scene in here [
youtu.be]
33 UStons and 67'11" long, powered by twin 114hp 6cyl engines, one per truck, capable of sustained 62mph. 6 built in 1938, 4 survive.
Just imagine
cruising along the Los Pinos valley in one of those.