I uploaded volume 1 of ‘The History of Hut 6’ and parts of volumes 2 and 3 in scribd. This is a postwar history of Hut 6 of Bletchley Park, the British codebreaking organization. Written in 1945, declassified in 2006.
Hut 6 attacked German army and airforce Enigma keys.
The files can be found at British archives HW 43/70-2.
Similar studies for Hut 8 which was responsible for the Naval Enigma can be found at www.ellsbury.com :