If I remember correctly (no guarantee!), when we arrived at OCTU, Jurby, in mid 50's, we were asked if we possessed suitable civilian headgear, if the answer was no (pretty general!), the next day the Station tailor had a queue outside his "shop" and issued suitable headgear (trilby) to all. In hindsight it was quite a novel and amusing experience! Those were the days (I think!!!).
Bill