Yesterday I discovered this E-book 'Letters Home: Frank Goodridge's wartime letters, 1943-6', which was privately published by his descendants in 2018 and is available for free on: https://www.academia.edu/37845165/Letters_Home_Frank_Goodridges_wartime_letters_1943-6 I only skimmed the book for the information sought on an obscure part of the war and just afterwards. Frank served in the Intelligence Corps for most of WW2 after 1943, finally serving in 266 Field Security Section (FSS) in Iraq (for a few weeks in 1946 before being demobbed) and 283 FSS in Persia (October 1944-January 1946). 283 FSS was based near Abadan (the main refinery) amidst the oilfields operated by the Anglo-Iranian Oil Company and they were the last British troops to leave Persia - which was how I found the book whilst doing research on other matters. The Persian oilfields were a key British asset, second only to the British Isles in 1941-1942. Taken from: https://defenceindepth.co/2017/12/04/iran-and-iraq-during-the-second-world-war/ The British and Indian troops in Persia, were part of PAIFORCE (Persia and Iraq occupation force), were reduced to five thousand by December 1945. From: Espionage and Counterintelligence in Occupied Persia (Iran): The Success of the Allied Secret Services, 1941-45 by Adrian O’Sullivan (Published 2015). The role of the FSS is well explained here, although in a West European context: Field Security Operational Duties and such units were very small. I found one photo of twenty-five men, probably one officer and all NCOs. The authors had not used the Intelligence Corps Museum, so I have updated them and they have added the E-book to their collection.