This page is no longer actively maintained. (Pardon?)
Here's a small guide on how to disassemble a Zorki-S. So far I can only show you how to take off the top and separate the body into its three main components, but I'll add more as I get wiser. Not that I ever expect to really understand how a cloth shutter works... If you do, then you can contact me through the usual channels, and further this communal (not so communal) site.
Taking the top off of a Zorki-S is so simple that even I, the archetypical left-handed fool, can do it without losing too many parts, making dents everywhere, and cutting myself. Trusting that you're a better repairman than I am, I present you these instructions. As usual when embarking on adventures with screwdrivers, be aware of the magnitude of what you're getting in to. Your camera could be at stake! So don't try this on your Leica, don't keep me responsible if it goes wrong, don't sue me in court ‒ you know the rap.
Taking the top off a Zorki-S is like taking candy from a sweet, complacent baby. To make it even easier, I'll do it all in bulleted list form. To close the camera back up again, just follow the numbered steps in reverse order.
Update: this page shows the operation in graphic detail.
Now you can clean the camera on the inside, and see if the Krasnogorsk laborers left any secret messages. Happy repairing!
The rest of the body comes apart in three pieces: the base plate, that you can easily remove; the top plate with the shutter, and the cast oval body. To disassemble, unscrew the five screws in total in the rim of the top assembly; unscrew the four screws on the front facade, and unscrew the lens mount. Take out the lens mount supports, dip in the rangefinder to clear the upper assembly, and lift the parts off each other. The drawing, the idea of which I obviously stole from from Rick Oleson, shows how.