Back in the day MDC made a number of freight car kits using metal castings. Except for the drop-bottom gondola I don't recall anyone ever identifying prototypes for any of the MDC metal cars.
I searched the archives and came up with some information/suppositions about the later plastic model's prototypes.
I am specifically interested in the old Roundhouse stock car with metal sides and the single-sheathed box car with metal truss and wood sides. Does anyone know if either have a prototype and if so, what?