The spin recovery procedure taught on RAF Chipmunks in the 1960s closely follows the method in the 1936 notes except in one aspect: having applied full rudder against the spin, after a pause the stick is moved
progressively (rather than abruptly) forwards until the spin stops. Perhaps the Chippie's spin characteristics are different from US pre-war trainers. The PN says max number of turns permitted was 8, but IIRC we were taught to recover after not more than 5 turns (presumably because the a/c would continue spinning for a turn or two before recovery took effect).
Pilot's Notes: Chipmunk T Mk.10