For fabric covering we use round tube, so the out side gusset just folds around, bend it by hand. for alloy skin the square tube sits on the sides. To do it the other way is a real pain. For about the 8.5k you will only need paint and a seat cushion. and go. Options may be wheel spats, brakes if you want them, doors. Yes it has to be able to go on the trailor for the days flying, this has made me come up with a very simple control rigging, not with cables, but with two push rods in the fuse vertical and just clip on the end of the aileron horn.