RE: PT40 dihedral
I agree with johnbuckner. If the wing is already built: LEAVE IT ALONE
If it is not built, I would build the B wing and use ailerons. But, I would build it as designed with the single aileron servo. On this plane I do not believe there is any advantage to dual servos. The setup delivered in the kit requires less work, saves weight, saves money, and works fine.