Pete-
Thanks for your thoughts. We are headed in the direction of selling the elevation ("flat") with the window and trim details as a separate kit. Then, the customer will have the choice of the 1" deep shadowbox or 6" deep building. The building would have a back elevation with simple windows.
The reason to sell the behind-the-elevation parts as separate kits is that there are separate floor, ceiling and roof pieces. This new building has a total 11 of those.
The next building that we are working on is a historic hotel in Kansas City. It is located on a corner so the building kit would have two main elevations, a rear and a side.