budcop, the rudder is a very close fit into the fuselage fairings and requires a close fit if you want it to look right. If I am not mistaken, the gap between the rudder and the fairing on the real Gee Bee is only 1/8 inch. The fitting process is complicated by the shape of the rudder cross section which is sort of like 1/2 of an elongated hour glass. It is not really hard but it does take a lot of fitting and fussing to get it right. As a matter of fact I am doing that very thing on mine at the present. BTW, the rudder contour shown on the plans is very close