This model was tooled in the mid 1990's as part of Walthers push into the N-Scale market (a somewhat short-lived push). Rumor has it that tooling and production were done by Heljan (Denmark). The doors were separate parts, and whatever adhesive they used attacked the plastic in the doors causing them all to warp.
There are two versions of this car - one with end loading doors and one without.
Here's what Walthers has to say about them -
Cars of this style appeared around 1929 on several western railroads, where they were used to handle automobiles, furniture and lumber products. Their double-wide doors simplified loading these cargoes, which did not fit well in smaller cars. Like most cars of this period, steel and wood parts were used in construction. Many remained in service into the 1960s.