Well, coincidentally, I have had a recent experience with a historical society and a car which Atlas first offered a few years ago and which I included in an article...A Tale of Two Hoppers in Ted Culotta's Prototype Railroad Modeling, Vol One. Atlas actually produced a rather nice model of the Rogers Hart 70 ton ballast hopper car, UP's HK-70-1 except, amazingly, they produced a model lacking bolsters and center sills. Instead of bolsters the car had what I called tubular uprights and, Regretfully, both the missing bolsters and center sills was very noticable...IMO. So, I added parts to simulate bolsters and center sills.
Enter the UPHS. They are now producing a special run of the Atlas car AND the missing bolsters and center sills are no longer missing. The lettering is correct also for the 1953 time period. Credit the UPHS.
I will note that the other hopper car in my article, a UP H-70-1, a 3 bay hopper car, suffered also from a strange fate. The area under the hoppers at each end contains a solid plate rather than the "L" shaped, open structural braces of the prototype. I have heard a rumor that this car's end design was due to some degree by the need to have a firm support for the very unusual coupler mechanism. Some say that a similar device was found near the wreckage of a strange looking craft located about 20 miles north of the UP mainline in Wyoming. At any rate, I was able to remove the models of the strange looking couplers, and replace the solid plates with open braces. The last step was to locate the Andromeda Galaxy on a dark night and throw them back as hard as I could.
Incidentally, the two hopper cars are rather important for the UP modeler. Oh, I have to admit that on pg 60 of my article, the last car in the string of UP hopper cars is...well...an N&W hopper car. Couldn't resist.