Maybe ready to go into an underwater case, similar to "Krab" for the Leningrad. Lens gears hook to controls for aperture and focus. Winding knob extension to hook to winder on the underwater case.
The thing on/around the lens looks a bit like the thing around the lens on a leningrad 'police'. Here's a pic from the minsk photo museum. Hope they don't mind me using this:
Seems like an interesting museum. Anyone able to go should go.
I can see the idea of the zorki being for underwater work, but I can't see how the aperture could be changed after it was put in the waterproof housing. There is an arrow on the front edge of the barrel and that must point to something. I presume this would be a distance scale. Though I also think this would have to be set before putting it in the housing.