I thought I'd take a few minutes to try out converting the interior walls. Here are some sample shots of 6" walls:
I've tried to avoid scaling the walls, but I want to keep some of the details. So, for example, I had to remove some of the metal pieces from the exterior of the wall when the door/window were there. But, it worked out OK. Also, I didn't scale the railing, and I pieced together the peeling wall areas. I think they are pretty true to the original. There are some challenges with the door and with some of the other window styles, but I'll keep plugging away. I think, ideally, I'll have maybe three different 6" walls, and four different 3" walls.
After I get these done, I'll try to convert the roof!