Wings,

Superiorbalsa.com has 3/8"x1 1/2" aileron stock. Add a 1/4"x1/2" to the fat side, touch up the corners of the 1/4"x1/2" with a sanding block and voila. Or, glue the 1/4"x1/2" to the trailing edge first and sand to match taper of the wing. Then add the 3/8"x1 1/2" aileron stock to that.