This camera was made from the FED 4b for Foto-Quelle, West-Germany.
This is the first version with "Revue-4" engraved on a plastic plate.
Same general characteristics as the FED 4L in the Wiki.
It was equipped with Fed/Industar-61 Zebra.
This camera is not very common.
Serial number of the pictured camera: 8325308 on the back (Jacques collection).
Serial #8445734 and lens #2201678 was bought from Foto-Quelle in June 1973 (original bill).
Known serial number range (please extend the range with your serials):
7-digit serial number on the backside of the top:
#6802105(fotoua.com) to #8445734(described above)