I did the solder iron trick again and peeled strips off the outside top skin, match drilled the holes to the ribs, deburred, dimpled and countersunk all the holes alomg the main spar. I also dab a small amount of primer in these raw countersunk holes to try and elimate any corrosion which may occur here. Both top skin are ready to rivet on, a good days work with no hiccups.
