I enjoy the challenge.
I always suspected that the building at Throop and Cortez alongside the Metra NW Line in Chicago was rail served at the raised level of the viaduct. When you go past it and look west from a window of a Metra train you see what look like loading dock type doors. It would not make sense to have wide doors on the second story of a building otherwise.
And in this 1952 view from NETR there appears to be a siding along the building with a tank car just to the north.