The very first production was different it had rounded corners and a fixed door wrapped around the bottom. Mikron was in script letters on the front with FED on the top. These cameras are very rare and represent a pre-production batch. It has a soft black vinyl zippered case (source: http://www.commiecameras.com).
Camera was pretty expensive, it sell for 85 rybley. Monthly earning for many in USSR at that time.
Produced: 1968-1986
Name: „ФЭД Микрон“
Producer: FED
Frame size: 18x24
Lens: Helios-89 1.9/30.
Shutter: 1/30s-1/800s + B.
Quantity: ±120.000 units.
Original price (in year 1986) 85 roubles. (Sovietcams.com)