I spent some time today sanding the trailing edges of both tips, and around the leading edge where I had applied some epoxy/flox to improve some minor fit issues around the leading edge.
Four ¾” wide, .020” thick aluminum strips were cut to serve as backers for the rivets to be applied ahead of the closer ribs. These were match-punched to the rivet holes in the tip, then glued inside the ribs with Gorilla glue. Clecos and clamps will hold them in position while the adhesive cures.