i'm also not so sure it's all that important for the ailerons to be tapered,....shaped as part of the airfoil. I've seen and used 1/8 inch stock for ailerons all the time and never had any indicators that would point towards a problem because of their un-tapered shape . the key and more important aspect,..... is to get them tight at the joint between wing and aileron to minimize the turbulence from a gap..