Johan, Thank you about the building!
Lew, You are absolutely correct. I am going to leave the roof unattached and not add a base so I can ponder an interior, which I never did in HO and especially N scale. Myles (Trainman2001) offers tremendous information about building interiors in his 'Continuing Saga...' topic. I think I will finish the exterior, so I don't lose the parts 
then set it aside while I think about interior treatments, methods, and materials.
John, I also am always so impressed and encouraged about all your painted passengers! I had a different thought than Mitch. The photo looked like a formal photograph at a sock hop from the days not long before I was in high school. Boys wore a jacket and ties, the girls wore bobby socks. (In my day, the fellows didn't need a tie and the girls were allowed to wear slacks instead of dresses that were required for classes. Both boys and girls could wear jeans as long as there were no rivets on the pockets that would scratch the bleachers.) Fantastic!
