@ Milt in Post #108
You say the nose wheel door acted as the air brake on the Gnat?
My involvement with the Gnat revolves only as a young spectator and later as a Halton Apprentice (plenty of Gnats to work on in 1984 during the 'airfield' phase).
I thought it was the main gear that extended partially to allow the main gear 'doors' (fairings would be a better term) to act as air brakes - or am I mistaken?
Perhaps it was all three gear doors?