I am hoping this is the correct section, my reasoning that the answer to this question can deal with aerodynamics. With this build I am doing, the p47, the plans show fibre hinges for the ailerons. Now in my P51, the elevator and rudder edges were rounded or triangled to allow them clearance to pivot if that makes any sense. For ailerons, they were angled at the pivoting edge, and then hinged at the bottom. This leaves, when the ailerons are even with the wing, as notch at the top, but a smooth bottom. I am having difficult coming up with this description, so sorry ahead of time, but which is better for ailerons, a smooth hinge along the bottom made from covering or decal, or hinging like the elevator and rudder?