Thanks to all for the input.
Here’s what I know so far -
The “later” photo dates to post 1963 - based on the fact that a large “pregnant tapeworm” interlocked CV is most likely the lettering on the car in the far left edge of the image.
The earlier photo likely dates to 1920 or slightly earlier based on the PRR GG class car, the ATSF Bx0, and the arrangement of the building - specifically the water tanks - shown in the 1920 Sanborn Map.
I’m going to assume that for the 1920s+ era the building looked more like the later photo than the earlier one - but ideally would like to locate a dated photo from between 1918-20 and 1963+ to confirm that.