I don't see any real difference between filling the gap with strips of wood and sinking the torque rod deeper into the aileron. In either case, you don't want the aileron rubbing against the back of the wing. Try as you might to make a hinging job perfect, there are always little flaws that keep this from happening! The aileron may have a small warp, one way or the other, the hinges may not be perfectly aligned, the hinges may not be dead center on the hinge line or may be slightly slanted from the centerline, etc. etc, this list goes on and on. Darock describes what might be the absolute best correction. However, since your gap is 1/8th inch, using 1/16th thick strip is the perfect way to fill this gap, putting 1/16th on the wing and 1/16th on the aileron. No sanding required and a perfect line for the hinge line, if the surface being glued to are perfect.