I had a conversation at a Cross and Cockade gathering some years ago, with Brad King of the IWM (The author of RNAS (Hikoki Press)etc). He had showed us some film of Felixstowe ( flying boats) in 1918 and he remarked that the amount of film they had to sift through would literally and with no exaggeration would take at least 10 years or longer.
I was quite disappointed to learn that the Flight photographic achive is now in private commecial hands and when given specific magazine, date, page, details they could not trace the negative.
John