War diary of Air Intelligence Unit(s) RAF.

[Jaap Woortman]

After the landing of the allied troops in Normandy in June 1944, RAF Air Intelligence unit(s) have investigated German airplanes and wrecks of airplanes on the Continent. The results were published in “Crashed enemy aircraft” reports. Some are surveys of large number of aircraft, some are reports about individual aircraft and some are a combination of both. These reports can be found in the British National Archive in London, the former PRO, in section Air 40.
I am looking for the war diaries of these Air Intelligence Unit(s) or Air Intelligence Officers who were involved in the investigations in the field in Belgium and the Netherlands. Many of the mentioned reports, published by Air Intelligence A.I.2(g) (section Aircraft and aeronautical equipment), were signed by Sqn./Ldr. M.Lambert.
Are war dairies or Operational Record Books(ORBs) of these unit(s) available in the NA in London?

Jaap