“It provides a fascinating insight into the life of a highly competent and personable young secretary working and travelling with key members of Churchill’s top team,” the C&T cataloguer wrote.
The collection included some very rare and historic passes and documents as well as letters.
Long also worked for Lt Gen Sir Leslie Hollis, Secretary to the Chiefs of Staff Committee (1941-42) and the Treasury (1948). Pictures include views of an uninviting Moscow Airfield in October 1944 with photos of Stalin.
The archive sold to a UK private collector for £4600 (estimate £800-1200).