Armstrong Whitworth Siskin Mk.IV/Mk.V

The development of the Siskin Mk.V started before the Mk.IIIA and was an improved version of the previous Mk.II. It had the shorter upper-wing span and broader chord lower-wing and parallel struts of the Mk.II together with a redesigned vertical tail surfaces, a forward fuselage with rounded sides and was powered by a 385hp Armstrong-Siddeley Jaguar III engine.
It was armed with two Vickers 0.303 machine-guns placed at the sides of the frontern part of the fuselage.

When it was presented, the Romanian government showed interest on it and ordered 70 examples. The production of those examples started in 1925 but in March of that year one Siskin V used as demonstrator that was piloted by a Romanian pilot, crashed, and the order was cancelled, with at least 10 examples being completed but without deliveries having been made.
It's known that at least two Siskin V were flown with civilian registrations.
The Siskin Mk.IV was an ad-hoc civil racing version made for the 1925 King's cup race and it looked similar to the Mk.V. It won that race.

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