Lancasters and Mosquitoes were the main PFF aircraft. The picture below, though not specifically of a PFF Lancaster, gives some idea of the personnel needed to keep these magnificent aircraft operational.
Top row, left: petrol bowser and crew; top row, right: mobile workshop and crew.
Second row down: Corporal mechanic, four aircraftsmen (mechanics), engineer officer, fitter (armourer), three armourers, radio mechanic, two instrument repairers, three bomb handlers, fitter.
Third row from bottom: Bomb train with WAAF driver and bombing-up crew
Second row from bottom: Flight maintenance crew, from left as follows: NCO fitter, mechanic, NCO fitter, five mechanics, electrical mechanic, instrument repairer, two radio mechanics
Bottom row, from left: Flying Control officer, WAAF parachute packer, meteorological officer
And then the aircrew: pilot, navigator, air bomber, flight engineer, wireless operator/air gunner, two air gunners.
(With thanks to David Layne, who discovered this gem in Lancaster – The Story Of A Famous Bomber by Bruce Robertson, published by Harleyford in 1965.)