ComoDepot wrote
...why build it as it never existed...
There was a lot less information about how it looked overt the years when the kit was produced. Much of it was based on how the roundhouse looked at the time, including the 3-sash windows that were probably installed after abandonment. It didn't have the hole where the door to the boiler hose was, but the intent was to allow the modeler to build it to whatever time or appearance they wanted. Also, this wasn't built by rabid South Park fans who even had all on the info available at the time. They were in business to produce kits, and the return on their investment of time was very low as it was, so they couldn't justify spending too much time researching all of the historical details. Before internet forums like this and on-line photo archives, it was extremely difficult to fo thr research. The target market also wasn't purists, as the original kit only had three stalls, which was thought to better fit into most model railroads.