In the December 2018 issue of Model Railroader, Tom Houle shows how he scratchbuilt an exact O scale model of the Soo Line train depot in Dallas, Wis. As an online bonus, download the cutting diagrams featured in the story, as well as the standard plans for a Wisconsin & Northern depot that he used as reference.
You can go visit the depot at the Triple H Ranch in Hillsdale, WI.
http://www.triplehhhenterprises.com/depot1.jpg
The plans for the Dallas depot appeared in a 1986 issue of “the Soo,” magazine of the Soo Line Historical & Technical Society.