Just like the tower walls, the last and final wall has to be wallpapered on all floors before it's glued in place. But this wall is even more difficult because not only does it fall on two floors, but also four rooms. I had to apply four different wallpaper patterns and make sure that I didn't use the wrong pattern in the wrong quadrant.
I wallpapered the attic, using tiny newsprint I printed from the computer.
Once this last wall was in place, I could give the dollhouse a coat of paint on the exterior.