You win again Trevor. It is indeed the Felixstowe 5.FL
The twin-engine F5L was one of the Felixstowe F series of flying boats extensively redesigned by John Cyril Porte at the Seaplane Experimental Station, Felixstowe, England during the First World War, from an original design by the American designer Glenn Curtiss.
The Naval Aircraft Factory further redesigned the Felixstowe F.5 for American production with numerous modifications made, including fitting 400 hp Liberty 12A engines. The American-built version was also known as the Curtiss F5L and (in civilian operation) as the Aeromarine 75.
The F5L was built by the US Naval Aircraft Factory (137) , Curtiss (60) and Canadian Aeroplanes Limited (30). Some were converted for civilian use by the Aeromarine Plane and Motor Company in 1919.
You have control.