It was quite a job attaching the support timbers by myself. Jamming the bottoms with a chairback while I aligned and attached the top to the runners worked surprisingly well. I was tempted to roll the roof off, but it was quite breezy today and I was by myself--any difficulties could have been a real problem. The side weather boards will keep the roof on the track, so I don't need to use side rails. Note that the run of is on the same side of the shed as the door. I wanted to have the door pointing away from the nearby country road for security reasons. As you can see in one of the pix, that horizon (the west) is also blocked by a plantation of trees (walnuts, hence the observatory's name--The Walnut Ridge Observatory). It made sense to have the runoff frame on the same side of the building. As you can see, access is not restricted by this arrangement.
The interior is finished. I attached hardboard to the insulated stud walls and taped the joints. Hardboard was not a good choice as it buckles a little in differing humidities, but drywall would have been an even worse choice! Here's the interior:
When I get the scope in as well as my desk and some posters, it should look halfway decent. Next steps--cleanup and then scope move!