These models were originally developed by "V-Line" as a kit. An outfit called "Loco-Motives" subsequently acquired them and improved the detailing (vis'a'vis the stirrups). Deluxe acquired them after that and sold them RTR in 1, 2 and 3-packs.
As you can see, the steps on the original V-Line model are a bit more primitive as compared to those on the retooled version -
Generally speaking, Deluxe Innovations split production of their models between the US and China (just how much of what was done where varies by model and production run). DI went out of business in 2017 and much of the tooling for their products was subsequently acquired by Fox Valley Models in 2018. However, due to legal and logistical issues with the overseas manufacturers, Fox Valley did not acquire the tooling for these hoppers (although they may eventually do so in the future).
Here's what Deluxe had to say about them -
This design had a life span that is truly enormous. The last cars of this design were built in the 1960's -- three decades after the first cars were built for Santa Fe. Quite a few of these cars are still in service. Because you have to stand on the roof in order to open the hatches, these cars were immune from the "No Roof Walk" rule of 1964, but a number would be scrapped when friction bearing trucks were outlawed. Amazingly, some cars are now being retired because they have hit the Federal Railroad Administration's 50 year rule!
The deLuxe models of these common cars are weighted with the same copper slugs used in our box cars for superior tracking and immunity to magnetism. Most releases feature more than one paint scheme variation within a road name. For instance, the Missouri Pacific set features cars delivered with MP reporting marks and painted "corrosion resistant gray" that is actually a tan color, and cars lettered for MoPac subsidiaries Missouri-Illinois and St. Louis Brownsville & Mexico (both carrying the traditional buzz saw logo) that are painted in a more traditional gray color. Some of the more modern paint schemes including Delaware & Hudson and National Bureau of Standards have the four-color ACI tags. ACI stands for Automated Car Identification and worked like a grocery store bar code reader using a color TV camera instead of a laser. Unfortunately, the tags couldn't be read if they were dirty and the system fell out of favor by the early 1980's. This aspect of 70's railroading is rarely modeled but we include it on appropriate cars.
Originally designed at the height of the Great Depression, the first ten cars of this design were delivered to Santa Fe in an austere black paint scheme. Covered hoppers have always been used for any bulk cargo that had to be protected from the elements. Some have the impression that covered hoppers are used mostly for grain. Nothing can be further from the truth. In fact, moving grain in covered hoppers has only been commonplace since the 1960's. Before that period, most grain moved in 40' box cars with grain doors temporarily nailed over the doorways. In the steam era, covered hoppers were used for cement, sand, clay, talc, and other powders. The cargo was loaded through eight square hatches in the roof. To empty the car, the hatches at the bottom are opened and the load spills out. At this point, some low man on the company ladder would have to climb into the car with a broom and sweep out the corners and the center sill. The American Car & Foundry covered hopper design was such a success that it became a defacto standard for years. Even Pullman Standard (ACF's arch enemy) built cars to the same design. The distinctive open triangles in the sides make these cars easily distinguishable even from a distance. ACF would also develop a version without the open triangles which was not as prolific as the version presented here. Amazingly, many of these cars are still in use today, in MOW and lineside service. Many have been rebuilt as ballast hoppers, including for SP, CSX, Amtrak, and Santa Fe.