Going back today to FED made cameras. The Zarya. Like the Zenit SLR, the Zarya is an extension of the original Leica based rangefinders. However instead of adding features, they removed them in order to produce a lower cost camera. The Zarya is a scale focus camera. Its very much like a Bessa-L. There is no rangefinder, just the scale marks on the lens. They were made from 1958 to 1961.
Being a FED made camera and not a KMZ made camera, I can not derive the year of manufacture from the serial number. The Zarya's had removable backs instead of the bottom loading like the original rangefinders. It uses the same 39mm mounts as the FED, Zorki and Leicas. With an extension ring, you could use the early Zenit lenses.