I had a similar situation. I used pc11 2 part marine paste epoxy . I used a degreaser then sanded, and finally cleaned. They applied epoxy in small applications. They have an epoxy that has aluminum in it, but could not find locally
So I used the JBWeld, I thought it would add some structural integrity back to it.
Finally finished all the wire wheeling and sanding, the neighbors are probably as happy as I am. Replaced 6 rivets that were bad, I put 5200 in the hole before installing the rivet.
I used RustOleum self etching primer on all the bare spots after sanding everything. Ready for paint.