Revueflex E is a rebadged Zenit E by Foto-Quelle, West-Germany.
The pictured camera #67041122 is possibly from the first batch.
While this camera was rebadged by a company from West-Germany it was bought in the US. On the catalog is written Foto-Quelle international. Years later Kalimar SR200 was rebadged for the US market.
Camera distinguished by all engraved letters and numbers, even on speed dial. It's made with better overall quality then Zenit E. Carrying case is different then on Zenit E, most likely is made outside the USSR and fitter to camera before sale.
Known serial number range (please extend the range with your serials):
#67041122(pictured) to #72120651(fotoua.com)
Foto-Quelle catalog 1968, page 10/11:
DM 229,00 camera with Helios 58/2.0
DM 14,50 case
Foto-Quelle catalog 1969, page 10:
DM 249,00 camera with Helios 58/2.0
DM 14,50 case
Foto-Quelle catalog Winter 1974/75, page 16/17:
DM 269 camera with Helios 58/2.0
DM 199 camera with Industar 50/3.5