Diddled with the form and made the first main/rear rib -- 6061-T6 0.025" Marked out with the usual magic-washer method and cut out with snips the old-fashioned way. Place marker holes for two 3" lightening holes -- which seemed to go well and with the flanging seemed to stiffen the rib a bit... may go back and don one 3" flanged hole in each of the nose ribs... doubt it saves a whole lot of weight, but easy enough to do with the hole-cutter/flanging-tool.
