The Zorki cameras, especially the Zorki 1 are the Russians little brothers of the Ukrainian FED.

During the German troops advance in 1942, Ukraine was fully occupied and opto-mechanical manufacturing plants including that of Kharkov moved to Moscow and Siberia.

As indicated in the FED 1 descriptions,  for a long period (from 1942 to 1946-47) the manufacture of cameras in Kharkov was stopped. Meanwhile the KMZ factory in Krasnogorsk Moscow suburbs took over for the manufacture of optical components for the Red Army while the other plants of the same type in the USSR could no longer provide them.
German engineers and equipment requisitioned as compensation for the war damage were the basis for the establishment of a leader industry in this field of activities.
Considering KMZ the loot has been mainly optical (lenses).

Early in 1948 will be produced the first cameras FED-ZORKI then ZORKI. The FED-ZORKI dated 1948 (the only one showing the double name) are well appreciated.

It is generally considered that the models dated between 1948 and 1950 are mainly made from German parts. Later on, the design and manufacture have been Russian.
It is also considered that the manufacturing quality of the Zorki is higher than that of their Ukrainian  cousins the FED. (reminder: Ukraine was part of the USSR since 1941).

The lenses are 39 screw mount strictly compatible with Leica bodies of the same type, which was not always the case for the Fed before the war.
Another feature of the Zorki (which explains their higher quality): they are intended for export.
All characteristics regarding the use of the the Zorki 1 are identical to those of the FED NKVD or FED 1 with the same variations on slow speeds, access to 1/1000 sec..

All Zorki 1 are then loaded by the bottom (nimble fingers required).
They are very compact devices and particularly well designed. The retractable lenses, the bags made from beautiful genuine leather, the nice chrome finishes make them beautiful objects.
My model is a Zorki 1d recognizable by the rim around the lens and its characteristic coating. The camera name is stamped rather than engraved. It was probably made in 1954.
Like all its brothers of the same period, it is imperative to change the speed only after having advanced the film.

This is the last version with staggering of the speeds in the typical Russian way (Z-20-30 ...).