Martinsyde F.4 Buzzard - Part one

The Martinsyde F.4 Buzzard was a powerful and fast biplane fighter that was developed for the Royal Air Force, but as the World War I ended, its mass production was cancelled. No more than 400 of them were produced and most of them were exported.
After the Great War, Belgium bought at least two of them to equip their Aviation Militaire (Military Aviation). They tested it at the Evere airfield but it was rejected for service.
The airplane was among of the few that founded the Bolivian Cuerpo de Aviación (Bolivian Aviation Corps) as nine of them served there from 1925 until 1929 when they were replaced by more modern types, most probably the Curtiss Hawk IA.
With its native users, only 57 of them were put into service with the Royal Air Force, but they weren't put into operational use. In the inmediate postwar, two of them were used as high speed transports during the Paris Peace Conference in 1919 and some others served in the Central Flying School. As the post-war RAF didn't want the type, it never served as a fighter.
The Finnish Ilmavoimat (Finnish Air Corps) bought a single airplane for testing purposes in April 1923 with 14 more of them being purchased in 1927. They initally served in the Maalentsoskadeer Ut until 1929 and since they served as trainers in the Kauhava School of Aviation until 1939. Nowadays, the Aviation Museum of Central Finland has the only remaining one in exhibition.

Sources:
1. http://www.belgian-wings.be/Webpages/Navigator/Belgian_Aviation_History/BAFAircraft/Bafallaircraft_1919_1945.htm
2. http://www.aeroflight.co.uk/waf/americas/bolivia/Bolivia-af-CMA.htm
3. https://en.wikipedia.org/wiki/Martinsyde_Buzzard
4. https://fi.wikipedia.org/wiki/Martinsyde_F.4_Buzzard (translated)