Kelvin Hughes RSA Plotter HMS Carnavon Castle. They were a British company specialising in the design and manufacture of navigation and surveillance systems. They produced the first type approved commercial radar in 1947 as well as the first paper tracing services in 1971. The purpose built box measures 15.75 inches square and the potter is 14.5 inches diameter, all in very good clean condition, please see the photos for all information. Carnarvon Castle was built by Harland and Wolfe, launched 1926, requisition by Royal Navy foe the WW2 in 1939, returned to owners in 1950 and served till 1963. So hope that is a true account and please let me know any further information, lovely addition to any marine or historic collection, many thanks for looking.