Zenit-E is very repair-able, but camera + lens might normally have a market value of ~€40, while cost of repairs could easily exceed €100, so not many shops will touch it.
The easiest thing to do is simply buy another camera from someone who specializes in Soviet cameras, and who has already performed any necessary repairs.
But if you really want to keep your existing camera and are good with complex mechanical devices, it might be possible for you to repair it yourself. You will need some miniature screwdrivers and a spanner wrench in order to remove the top cover of the camera.