I bought a vertical recce photo of thorney island from IWM,cant show here (copyright) but I have marked a GE image to roughly match the photo.

The area outlined in Red is all Grass ,the apron which is there now presumably added in the 1960’s.
The black square with cross inside looks like a blister Hangar on the photo.
The other 2 smaller black squares appear to be square huts,with small aprons in front of them.
Comparing that to the image in the above post…looks very similar ?