Quick, accurate, way to align the spats. Measure the fuselage width where the wings pass thru it, the width between the plywood wing seats, of the fuselage, through the actual fuselage. On the 50cc size, mine is close to 40mm wider at the front, leading edge than the rear, trailing edge. Then put a fine pen line on the underside of the wing panel from the leading edge wing root, back to the trailing edge, BUT 20mm in from the wing root, at the TRAILING edge. You now have a line marked parallel with the fuselage centre line to work from, to align the spats with. Easy as.