The 'hard part' is done - framing the roof. Ok, so it really wasn't that difficult, but it certainly wasn't an exact science. The Sketchup drawing helped out to give some hints on how long the beams should be, but due to slight variations in wall length and alignment along the way, some trial and error was needed. Fortunately there is a little wiggle room when getting things lined up given the flexible nature of the metal roof.
As can be seen along the bottom edges of the walls are going to be what I believe are rain gutters. The walls along the concrete areas in the source photo seem to be tarred or somehow sealed against water penetration. That should add some interest to the long stretches of brick.
To hold the balsa wood frame together, I use Loctite Super Glue Control Gel. It dries very quickly (too quickly sometimes) and forms a solid bond. Trying to do this with white glue would make it very difficult to get things put together in any reasonable amount of time. If I had the tin ready, I could have begun attaching it about 10 seconds after as I glued the last cross timber in place.
Next getting some tin on and remembering to leave space for the chimney is on the todo list.