M.A.G.-Fokker D VII – The D.VII was such a formidable aircraft that the Armistice ending WWI specifically called for all surviving D.VIIs be delivered to the Allies. The United States pick up a few for testing, but nothing ever came of the effort. However, other countries used them operationally. One country, the Hungarian Soviet Republic (1) used a number of D.VIIs in the Hungarian/Romanian War of 1919 (2). Some of these aircraft were ex-German aircraft and some were built by Hungarian 
MAG (Magyar Általános Gépgyár) an Austro-Hungarian company licensed to build the D.VII using the Austro-Daimler engines (distinctive radiator is only difference). It was from early 1919 to July 1919 that the Hungarian Soviet Republic used their D.VIIs emblazoned with the red star as seen on our paper model (3).
(1) – The Hungarian Soviet Republic or literally Republic of Councils in Hungary was a short-lived (133 days) communist rump state. When the Republic of Councils in Hungary was established, it controlled only approximately 23% of the territory of Hungary’s classic borders.
(2) – The Hungarian–Romanian War was fought between the First Hungarian Republic and the Hungarian Soviet Republic and the Kingdom of Romania. Hostilities began on 15 April 1919 and ended on 3 August 1919. The Romanian army occupied eastern Hungary until 28 March 1920.
(3) – The M.A.G. FokkerD.VII Mat. 93.07 was crashed by pilot Frigyes Hefty during an emergency landing on July 1919.
Notes from Wiki.
Mag Fokker
