Rebadged FED 4b for Foto-Quelle, West-Germany.
This version has a white silkscreened Revue 4 logo on a plastic plate.
It was equipped with Fed/Industar-61 zebra.
Foto-Quelle catalog Winter 1972/73, page 32:
DM 149 camera with Industar-61
DM 24,50 case
DM 99 Jupiter-12
DM 159 Jupiter-9
DM 119 Jupiter-11
DM 69 Uni-VF
Foto-Quelle catalog Winter 1975/76, page 14:
DM 159 camera with Industar-61
The pictured camera is type-2b from fotoua.com.
Known serial number range (please extend the range with your serials):
7-digit serial number on the backside of the top:
#8590214(fotoua.com) to #8677606(fotua.com)
6-digit serial number on the bottom plate of the back door:
#??????(source) to #??????(source)