You all are very quick on the uptake! Thanks for all the leads.
Tarkey: the A4 scan is probably what I'm looking for - can't wait to see it.
John: thanks for the Crown photo. I'll see what I can do with it. From whom do I have to get permission to use it- the Queen? (only half tongue-in-cheek)
Richard Flagg was kind enough to send me a site plan. I spent a good deal of time lining up landmarks from Google Earth with those in the plan. I'm still not completely happy with it - particularly the position of the E/W runway - it does not match the position of the scrap of that runway that is extant today.
Also very apparent is the length of runway added in 1955! The runway used to stop well short of the wood with the hospital in it (as you can see in the overlay).
I'll see if the scan that Tarkey's getting me will provide better matching.
I don't see a way to attach a file to this post, so anyone who would like have this initial 'try', drop me a message with your email and I'll send it over. (Tarkey, I'm already sending you one since I have your email address - and Richard too!)