It is the unique film "Night Bombers" with, it seems some extracts from the original wartime " Memphis Belle" film.
Night Bombers was filmed by Air Commodores Iliffe Cozens, the commander of 15 base [the airfelds of which were Scampton, Hemswell and Fiskerton]. The station commander at Hemswell was Gp. Capt. W. C. Sheen [seen in the film].
The briefing part of the film was made on 9th. Mar. 1945 after cancellation of an operation just before briefing. Cozens made use of the cancellation to make his film sequences.
The squadron shown is 170 commanded by W/Cmdr. Templeton-Rooke.
All this information is taken from the book "Bomber Intelligence" by W.E.Jones, the Hemswell intelligence officer at the time - he, also, appears in the film.
Incidentally, Cozens was the C.O. of 19 Squadron,at Duxford, when it became the first unit to equip with the Spitfire.