And a bit of Chippy trivia while I remember it. The Chippy was designed by a Pole, Wsiewolod Jakimiuk who designed the funny looking PZL fighters that were shot down in vast numbers by the Luftwaffe when the Germans invaded Poland. He escaped to England and redeemed himself by designing the Mosquito, the Chippy's heritage is evident in the shape of the tailfin which is the same shape as the Mosquito's.
The original rudder gave poor spin recovery. So the chord was extended by a couple of inches to add extra area, hence the angled notch at the base of the trailing edge. Also, the RAF added the anti-spin strakes (similar to the Tiger Moth's) extending from the tailplane leading edge. These work by creating a vortex at high angles of attack and energising the airflow over the rudder while in the spin. But they lead to the rudder having a short delay in it's effectiveness, which is why the recommended spin recovery technique is to apply full rudder, then pause (we used 2 seconds) and then move the control column centrally forward until the spin stops.