I have one that was made for export, so I have a bit more information on it.
On mine, the sensitivity is below the lens. You just align the line with the DIN value. On top, there is a sailboat, sun, snowflake, light cloud, middle cloud, dark cloud that correspond to the aperture.
From experience, the lens is pretty much equally good at all apertures, so I use it.
The camera has variable shutter speeds they say, but listening to mine and looking at the shutter, I don't think it's the case. If it is, it's going to be one of those slow-fast deals, so not really good for most situations.
As for the GOST values, mine has a handy conversion chart on the back. Here's a scan of it
Mine also has a place for a cable release... I just put a nice fat soft release button on it to make it easier to use.
Hope this helps...