This model dates back to the early days of N scale (late 60s / early 70s). It was originally imported by Atlas, and later on by Walthers (in Roco packaging). In 2009, Atlas released an all-new Chinese-made double door box car as part of their Trainman line (similar to this Roco car, but not the same).
I don't know which specific prototype this car might be based on (if any), but it looks a bit like a PS-1. One of the most successful freight car designs of all time, over 76,000 PS-1s were built by Pullman-Standard between 1947 and 1968.
Here's what Walthers has to say about them -
Built for auto service, these cars were later used for bulky loads like paper.