A Dutch flute!(Yes, they do exist!). This flute is told to be made in 1950, which is rather late for this kind of flute. Mathijs (Mathieu) Joseph Hubert Kessels starts as a music publisher in 1880 in Heerlen (The Netherlands). In 1886 he moves the business to Tilburg. When two men from Saxony (Germany) looking for a job as musical repairsmen come knocking on his door in 1887 he starts with the repair and production of woodwinds and brasswinds. Everything goes well and the company flourishes until his main financer, the Tilburgsche Bank, goes bankrupt. He is forced to take another partner into the business, but ends up with severe financial problems. In 1914 Mathieu Kessels is made redundant by his own company. Almost immediatly, in 1915, he starts again with a new factory, the 'Nederlandsche Fabriek van Muziekinstrumenten'. He is forced to change the name in 1931 in 'Nationale Fabriek van Muziekinstrumenten' due to a conflict with his former associates. Trouble take it's toll and Kessels dies on December 21st 1932. The company is taken over by his son Mathieu Jr.
The flute is probably made between 1931 and 1940. It has the mark 'Nationale Fabriek - Tilburg' indicating that it is made after 1931 and is at high pitch (A=452), so it would have been made before World War II. It doesn't have a serial number. further information (in Dutch) on Kessels can be found at: Gemeentearchief Tilburg and at the Muziekinstrumentmakersmuseum

(thanks to W.van Hulst for additional information)