The guns were formerly the property of Sir Thomas Sopwith (1888-1989) who was one of the greatest figures in aviation history. His inventiveness and his passion for flight were instrumental in producing a series of vital technological advances in this field, including the Sopwith biplanes of the First World War, the Hurricane and Typhoon fighter-aircraft of the Second World War and the development of the jet-engine in later years

Purdey's have kindly confirmed that guns No. 24941/2 were completed in 1935 and that gun No. 25063 was built in the same year as the third gun to the pair