Special macro lens for the FED 1938/1939 production. This special lens is not rangefinder coupled but goes from infinity up to 1:1 scales in continuous focusing.
The optics is the renowned Industar 10 3.5/50.
Non numbered macro lenses can be found. According to some sellers, they could have been made in 1949 or 1950.
Registered serial numbers:
107----------DVD (proto?).
12075-------seen on eBay.
14568-------Jacques Morin collection.
14764-------Alain Berry collection.
15136-------DVD collection.