The fiberglass came out just fine, especially the corner I was hoping to clean it up so I stripped off the peel play and did a little bit of sanding. Then I added the nutplates to the front of the top cowling and the two places where the hinge pin tab is locked down.

Then I reattached the hinges and used every other hole for a cleco, countersunk the holes and started riveting.

Looks good. Lots more to go.