I'm building a kit from the 80's - Craftair Firebird. The rudder and elevators are constant thickness balsa. Rudder is 1/4" and elevators (2) are 3/16". They need to be turned into "wedges" with a thickness of approx 1/8" at the trailing edge for rudder and 1/16" for elevator TE.

The top is where it would be beveled for hinging. What is the best way to get an equal angle on each side?