sealing ink on acetate - Model Railroader Magazine

Two possibiities:

Instead of printing directly on the window material, use decal paper, and apply the decals to the windows.  I do this a lot, and it works very well.

Flip the image horizontally, so it becomes a mirror-image of what you want.  Print that on the acetate, and then install it from the inside.  When you turn the building around, the printing will be correct, and the image will be protected from smudging because it's inside the glass, not on the surface.