I am working on a 40% scale Cassutt racer as an IMAC / sport pattern aircraft. The full scale aircraft has a flat stab and elevator made from a round tube frame work covered with fabric. I am planning on making mine with balsa sheeted over foam or a balsa framework. Should I just use a flat elevator and stab, or taper the elevator surfaces some? The planform shape of the elevator does not lend itself to an airfoiled section or I would do that.

Thanks,
Mark