I'm taking a few days off the tree bog now, but this is what it'll look like in the meantime:
The chicken wire sandwich around the lower part is waiting for the straw, which is waiting for the roof and walls, which are waiting for the floor, which is waiting for the anti-wood-boring-insect treatment, which is waiting for the rain to stop, which isn't going to start until tomorrow.
So far, I've only made one massive mistake. It's that post in the corner furthest from the camera, which is many, many inches too low - something I couldn't tell from ground level. Not sure how I'm going to pull off a patch job on that. I'll have to turn it into a feature somehow - a cup holder for Very Tall People, perhaps.