Cleaned up the panel, deburred and prepped to assemble. Used the Dynon module template to mark the layout, cut-out the center and sprayed the pattern onto the panel, outlined that with Sharpie, too.
Drilled corners for radius, and used a unibut to remove most of the material. Then Vixen file to clean-up before starting the more careful filing of the opening. Center punched the location of the screw holes for the nutplates.
