In other words, are these just symbols useful within the program or for scratch-building, or can I buy these structures somewhere?
A quick Google search for "TruScale Model Railroad Buildings" only turned up a few vintage items on eBay that appear to be from the 1950's or 60's.
Well - TruScale is just our marketing term for libraries containing items that can be used in any scale
Some of the buildings are (somewhat loosely) inspired by structures in various model scale, though these are only available in one particular scale. The general idea behind TruScale libraries is to provide a wide selection of items that can be used to decorate the layout, which can be replaced at build time with similar items by various manufacturers.
Since there are many manufacturers of structures out there - each of them usually with a huge selection of items for a number of model scales - it is unfortunately not feasible for us to provide libraries for dedicated product lines.
Best we can do with limited resources is attempting to cover very specific items like roundhouses or loco sheds where it's valuable to have the exact footprint when planning layouts.
Hope this helps,