Fabulous job Norm. You must feel so proud. As I mentioned some time ago we had an ice collapse on our boler
roof which after popping it back up left a sag in the roof. We added a Fantastic Fan a couple of years later and the sag became a real problem in that it was now deep enough that the water filled up and spilled over the edge of the fan into the interior and landed on the bed. Not nice. After reading the many suggestions on how to get rid of the sag we went very simple and it works. We propped the roof back where it belonged, used two pieces of square aluminum tubing (one for each side of the fan) on the "inside", bowed to the proper curve, put tabs on the ends and bolted that through to the outside of the "bump" with matching tabs for strength and voila, no more leaks
We had a big wet dump of snow this winter and that roof went nowhere. Since we have a taupe carpet finish inside, we never painted the braces and nobody really seems to notice them up there. We don't do fiberglassing so this was the best solution for us.