Jim, all good advice above!
All I might suggest you consider is that you dope or epoxy woven fibreglas (.5 or /.6 oz/sq yd) on the sanded flaps after basically shaping them. Comments I've seen make sense. CF, by itself, does not have stiffness "directions." Woven fibreglass does. Fibreglas also has its own strength, where CF (a mat of random fibers) does not.
Both fibreglas and CF rely on the 'binder' as much as on their inherent strength. For fibreglas, dope is adequate to hold its greater strength to the structure, but dope does have a tendency to warp. Properly done, using medium cure epoxy (30 minute or thereabouts) you can jig the flaps true, and they will cure - and stay - true.
Jigging them true may involve binding them onto the rods, separated by plastic wrap or even waxed paper, but should be certain.
And, as with iron-on coverings, the surface should be as smooth and dust-free as possible. Any flaws will show at the finished surface.