Simpley stated, the best solution is  to overbalance per the instructions
with the trailing edge about 1/4 to 3/8th inch above the pivot line then
paint the aileron and finish the sanding and buffing to the desired measure.
Then balance the aileron again and from there; file, grind off the excess
weight from the counterweight till the aileron trailing edge is horizontal
to the pivot line.  That should do the trick.

Bob Smiley
N94RJ.