BAT F.K.22/23 Bantam

Friedrich Koolheven's first design for the British Aerial Transport Company (BAT) was the F.K.22 single-seat fighter. It was a two-bay wooden biplane and was planned to be powered by a 120hp A.B.C. Mosquito radial engine, but, as that engine failed, it was fitted with a 170hp A.B.C. Wasp I in the first and third aircraft, while the second aircraft was fitted with a 100hp Gnome Monosoupape rotary engine and was the first aircraft to fly at Martlesham Heath in January 1918.
Originally six of them were ordered as development aircraft but three of them were built as the F.K.23 Bantam I with the second prototype being renamed as Bantam II. The Bantam I had the same wooden structure but it was slightly smaller. Two more prototypes were built, followed by at least 9 development aircrafts. One of them was delivered to the Royal Aircraft Establishment on 26th July 1918. One more was delivered to Villacoublay, in France to be evaluated by the French Aéronautique Militaire and a further one more was delivered to the United States Army Air Corps at Wright field in 1922.
Given the unsatisfactory spin characteristics of the prototypes, the production Bantam had to be modified. However, due to continuous engine problems and the downsizing of the Royal Air Force after the World War I, made that no further orders for the Bantam to be placed. Koolhoven returned to the Netherlands after the war with one aircraft which was re-engined with a 200hp Armstrong-Siddeley Lynx radial engine and several examples were used as civil racing aircrafts.
As we couldn't find graphical evidence of most of these ones, the French, Dutch and American ones should be considered as speculatives.

Sources:
1. https://en.wikipedia.org/wiki/BAT_Bantam
2. Salamander Books - The Complete Book of Fighters