E&C Shops was the original manufacturer of these models, with LBF and then Hubert's Model RR Mfg Group purchasing the tooling and continuing production later on. It is my understanding that (as of this 2015 writing) Intermountain has acquired all of the old LBF/Hubert's tooling and plans on re-releasing these cars at some point.
These cars cars are based on a National Steel prototype built for TTX and CP Rail (et al) circa 2001. They are used to transport heavy loads of roll paper, lumber, and other commodities that don’t require cushion underframes, interior bulkheads, or other types of specialized load-restraint devices.