World War 1 Studio Portraits - Not Yet Known

The Army Museum has an extensive collection of formal photographic portraits of servicemen and women mainly from World War 1 dating from 1914 to 1919. Many were taken in local photographic studios prior to departure overseas. Some images were captured in studios at training camps (like Blackboy Hill), in theatre (London, Cairo, Paris) or near the front as those recently rediscovered in the Thuillier Collection (https://www.awm.gov.au/visit/exhibitions/remember-me). Unfortunately as these portraits passed through generations, the names of many of the sitters have become lost. Though the names are lost, their service and sacrifice are Remembered. Clues or assistance with identification are always appreciated.