Leningrad loose spring - can't open knob

Hey all, don't know if anyone has experience with these camera's but I might as well try.

I took a leningrad camera home from the store I work at, mostly because it's cool.The camera is not functioning, a colleague probably overwound it while testing.

I took off the top plate and can see the following. The spring inside the big knob came loose from the slit in the rod it's supposed to be in, the rod is now loose and I can just pick it out. To put the spring back in it's place I think I need to take the big knob off the top plate. I found very little about this except one post on ussrphoto that mentioned it could be removed by unscrewing the 2 screws on it and just pulling it off. When I try this it just won't come off, it has a bit of play but that's about it.

Does anybody know how to fix it?

(I know this camera is very unlikely to work at all )

Can you post photos? Someone might see an approach even if they don't know that particular camera.

Have a look here:



Or... maybe not. I could have sworn it had repair notes on the Leningrad...