Laurence, I think your possible Lodestars are actually Venturas with the upper turret removed. Note the belly bulge just forward of the tail wheel.
The RAF took delivery of 394 Ventura light bombers, which entered service in 1942.
Lockheed PV-1 Ventura/PV-2 Harpoon - history, photos, specification of the Lockheed PV-1 Ventura/PV-2 Harpoon