Cut and sanded plastic tip rib to shape. Process was frustrating and messy! Attached tip rib to skin. Flipped over rudder and attached skin at trailing edge. Made an initial error with placing the spacer under the tip of rudder instead of base of rudder. Huge difference! Also, Zenith told me not to worry about whether skin edge on rear skin is perfectly square to spar (they emphasized the correct use and thickness of the spacer block).
