I've made some adjustments to the mockup that I showed last week - primarily lowering the overall height of the building since it just didn't "look" right. The sketch is really an outline of the shape of the wall - the doors etc.. are not to scale at all!
I have the rear and side walls completed - here is a mid-progress shot of the street side wall.
One little detail that I almost failed to notice - the right side of the building (with the clapboard in this photo) is older than the "overhead door" section - and it has narrower clapboards than the section to the left. But I needed to get the two halves to end up with a flush surface. The first attempt was to build it like the prototype - but the series of angles where the two halves of the building join together didn't look right.
I scrapped that attempt and went with the approach shown here - basically a subwall for the entire facade of the building with the two different sizes of clapboard laminated to it.