There was a blister hangar still in existence up to the late 60s early 70s that stood in the corner of the junction of Convent Way and North Hyde Lane, see
The Airfields Of Greater London Heston
and zoom in to the center of the northern boundary.
The odd 5 sided shape of tarmac is on the spot, but you can just make out the original dispersal as the top of a "hexagonal scar" on the grass partly obscured by the tarmac. Would this have been the hangar?
Where was the scout hut?
A semi derelict Cierva Autogiro, G-AHMJ used to be seen in a yard owned by Aeradio Ltd to the North side of HAP and was owned by the local Scouts (or Air Cadets?) and was restored and is viewable at Airliners.net
see Aviation Photos: G-AHMJ