It's been a week he says...
For the record, I do have a day job. And I live in Indiana, and don't have access to covered storage. So I only have evenings and weekends and clear days to work on this thing.
That said, there has been some good progress.
Damaged steel replaced, all frame parts wire brushed and primed
First side clamped in place. I was thankful it was on the cooler side this day, so the Gorilla glue didn't set up too quickly and we had time to get everything clamped up. We poured the glue into a plastic cup and used chip brushes to brush it onto the frame, then lifted the side in place and clamped. It helped a lot that we had the front and rear caps off. Also, the deep reach clamps from Harbor Freight that someone else recommended were a big help.
One other thing to point out in this picture: with the wall panels removed and the upper section only supported and the very front and rear, there was a fairly substantial sag in the middle. I used a floor jack and a piece of wood to support the upper section in the middle while we clamped the wall in place.
View from the "port" side with the "starboard" side glued back in place and clamps removed.
View in through the door. The 2nd side has now been glued in place, and the first piece of insulation board is glued and clamped in place. This will be a longer, more tedious process than I'd hoped.