That 8V 50W lamp is designed for an 8mm home movie projector and was very popular in Europe at one time. It is better known as a CXR or A1/17 bulb, or Philips type 13113C/04. It is probably the most optically advanced bulb that has ever been made, becuse its rear ellipsoidal reflector and hemispherical front mirror produces a very narrow beam with almost no light loss. The chimney on the top ensures that the bulb doesn't blacken as it ages becuase nearly all the evaporated tungsten rises upwards and is deposited here.
The lamp is still available from Philips in Europe but they don't actually make it themselves any more. The last company making these is Fuji lampworks in Japan and they supply it to GE, Philips and Sylvania. Your lamp looks like it would have been made by Philips Holland or Belgium around 1970.
Hope this helps!