This camera is really original.

The mechanism is a Fed 1f one, and so is the belt. But the rangefinder (with its Leica like arm), the bottom (see the inscription "made in Japan"), and the cover, belong to a Nicca, without any doubt.

It could have been mounted in 1949, by the Nicca serial number on the cover. And the Fed part could be from the same year too. But by whom? I have read that some Niccas were made with "foreign" parts after WW2...