In the following September, an initial order was placed on behalf of the RAF for 30 Gamecock Mk.Is powered by the 425 hp Jupiter VI. In the event, a further 60 Gamecock Mk.Is were built for the RAF in 1925-1927), one of these (unofficially known as the Gamecock Mk.III) at one time flying with a lengthened fuselage, new and enlarged fin-and-rudder assembly and narrow-chord ailerons.
A developed version, the Gamecock Mk.II, with a steel-tube upper wing centre section, narrow-chord ailerons and a larger rudder, appeared in 1928. This was adopted by Finland, two pattern aircraft and a manufacturing license being acquired. Fifteen Gamecock Mk.IIs were built for the Finnish air arm 1929-1930 by the State Aircraft Factory (Valtion Lentokonetehdas), these having the lengthened fuselage tested earlier in the UK by the so-called Gamecock Mk.III and being powered initially by the 420 hp Gnome-Rhone Jupiter 9Ab or 9Ak and later by the 480 hp Jupiter 9Ag (license-built Bristol Jupiter IV engines).
The pictured aircraft was assigned to the No.3 Flying Training School. On Wednesday March 25, 1931, Captain Kitrell took off from RAF Station Grantham, Lincolnshire, England, but allowed the aircraft to swing to the right, a tire burst due to excessive strain, and the aircraft overturned.
The last Gamecock Mk.Is were withdrawn from first-line RAF service mid-1931, Gamecock Mk.IIs remaining first-line Finnish equipment until 1935. The following data relate to the Gamecock Mk.I.
Span: 29 ft 9.5 in (9.08 m)
Length: 19ft 8 in (5,99 m)
Height: 9 ft 8 in (2,94 m)
Wing area: 264 sq.ft (24.52 sq.m)
Empty weight: 1,930 lb (875 kg)
Loaded weight: 2, 742 lb (1,244 kg)
Max speed: 145 mph (233 kmh) at 10,000 ft (3,050 m)
Climb: to 10,000 ft (3,050 m) 7min 36 sec
Endurance: 2 hr 30 min."