Internal walls cure wobblyness

Nice design feature alert - the completed walls slot into the underside of the roof. A ridge provides nice positive location. You can't go wrong, and there is plenty of contact between plastic bits for the glue to do its job.

Unfortunately, as you can see, once dry the walls are still a bit wobbly. The model doesn't sit flat on the board. Bending with my fingers helped a bit, but more work was required.

I had always meant to add some internal walls since looking through a building just isn't right. While not planning on fitting a detailed interior, I had pondered on cutting an archway in the main wall - a popular feature and one you'd be able to see from outside.

On balance, I'm sticking with solid walls from a nice thick plastic sheet off cut. A bit of careful measuring means they push the exterior walls out a bit at the bottom so everything is sort of square and the model sits on ground as it should.