I'm a glaciologist user of declassified US Spy satellite images (Corona Key Hole satelites, Hexagon, etc.), that provide an extraordinary record of glacier extent at resolutions equivalent to about 4 meters per pixel (see this amazing example). There are also ex Soviet Union declassified images from the '60s onward from satellites like Zenit-4, Resurs-F1, Okean-O1, etc. with similar technical specification than the US images or maybe better (they had color and NIR capability). However all my attempts to access such images end up in pages written in Russian that I can't understand or navigate trough. Some interesting information about sources of imagery is here (search for "Subject: Russian Imagery"), but with my null knowledge of Russian I haven't been able to find where to order such imagery, not an online catalog, nor to find if such catalog even exist.
So: Does anyone know how to access/order declassified ex Soviet Union imagery?
[EDIT January 25 2018: I've added and answer below with information I found regarding an archive containing part of the images but not all.]
As an example, here is a 1973 Zenith image taken over antarctica:
And here is a crop of the above image compared with Landsat 7 ETM+ at 30 meters per pixel. However, according to specifications, properly scan film should provide a much sharper and detailed image: