This grainy image from wartime footage shows Churchill at Oakington in 1942. The Stirling taxiing in the background has a 7 Squadron identification code of MG.
7 Squadron joined the PFF in August 1942. Although we have not yet confirmed this had happened by time this footage was taken, it would seem highly likely that Churchill, who was very much a hands-on leader, would have visited the new Pathfinder bases, including Oakington.
With thanks to Dave Cheetham for the information about the aircraft in the background.