The next step was to start custom-cutting special pieces out of the same, 3/8" square dowel, with opposing 45-degree cuts on each end, to then glue onto the sides. These would form the joists for supporting the patina-colored sides of the pented roof.
This is a lot of work, and there are probably easier/better ways to do it. Each of these angled joists has to be measured and cut very carefully, so that the top is flush with the top of the upper rectangle's surface, and the bottom is flush with the top of the bottom rectangle's edge. (Huh? Yeah, see the pictures...)
Once these are installed, the structure is very strong since there are so many components glued together. If I didn't care about the internal ceilings, then I could have simply started mounting the side pieces onto the joists.
I then used more of the square dowel to create a "nested" elongated octagon of sorts in the center of the ceiling. This was an easy way to create a coffered ceiling. This nested octagon was complemented with some crown moulding, and then the main ceiling piece (simple matteboard, with the octagon cut out) was installed.
The West Hall was the second one I made, and I decided to get a little bit more sophisticated with it. The lower ceiling has four recessed lights - one centered over each of the three palladian windows on the side, and one over the rear entrance. The coffered ceiling would sport two hanging chandeliers (Cir-Kit brand dollhouse items).
The East Hall roof and ceiling is different, both in appearance (slightly) and in construction. I tried a differenct approach with the angled side joists for the East Hall. I used a table saw to cut a regular 2x4 pine stud at a 45-degree angle, essentially ripping a triangular-shaped dowel from one of its' corners. I then sliced this into the triangular joists you can see in the photos.
This did not work out as well as I'd hoped. My thinking was that, if I was careful, I would get evenly-shaped precise copies of these triangular joists. But in practice, this did not turn out well. Maybe if I'd used a better quality wood, which I may try for another project in the future. The pine 2x4 stud split and notched significantly, and although the results were workable, I think the custom joists method used on the West Hall (and the 5 other pented roofs I've made) worked better.
The East Hall has a cut-away in the side, to expose 5 cell amplifiers. This is something I have seen on other pented roofs (the real WUS does not have patina pented roofs). The 5 cell amps are simply cut wood, painted white, with some black screen mesh glued to the surface. These are then mounted onto 1/8" square sticks. To get them to mount perfectly straight, and evenly spaced with each other, I ended up having a custom strip of plastic lasered with little square holes cut out of them to insert the stems of the cell amps into. This is a side benefit of getting CADs lasered into sheet styrene every month or so - there's always a little room on one of those sheets for some small extra parts.
That's the only lasered piece of the entire East Hall roof. There are two vents near the back of the East Hall roof, which are made of 35mm slide sleeves. I painted the slide sleeves flat black, then cut some screen mesh to about the size of a 35mm slide. I painted those screen meshes silver, and inserted them into the black slide sleeves, and then mounted these onto the roof.