RE: wing building
Sheeting and glassing does add to the strength but on the Corsair I do feel it adds too much weight. {Who Said That??} I'm not usually a weight watcher but I have had the 60 size corsair that was sheeted and glassed for racing. I didn't build it but after flying one with open bays I decided the weight added much too much to the wing loading. The lighter plane was a lot easier to land.