You've not glued it on? No problem. Set the impropery cut piece aside, and cut the correct piece of sheeting, trim the turbulator spars ( the 2 smaller ones on top of the forward 1/3 of the wing) and don't forget ti inset them into the sheeting as illustrated (4 to 10 times the strength of a butt-joint)

The miscut piece will work as a piece of sheeting on the other wing... the portion behind the main spar uses narrower sheeting. [img]i/expressions/face-icon-small-wink.gif[/img]

Don't short-change structure on the wing, especially near the center.