I used paint remover for fiberglass to remove the paint. But it didn't remove much. I ended up sanding it off. What a mess. The whole garage got filled with dust. Never again. Sanding of this magnitude needs to be done in a paint booth or outside.
There were lots more cracks visible with the paint off so they all got filled.
The aluminum flanges were loose and different in size. I made them all the same and re-revitted them in place.