some times ago I found a little paper inside a Fed's bag, this one:
front

http://www.ussrphoto.com/UserContent/1742013_Immagine 001.jpg
and back

http://www.ussrphoto.com/UserContent/1742013_Immagine 002.jpg
There are printed camera and lens characteristics, and there are written camera number(142265), lens number(141727) and issuing date(30/IX/40), but I don't think it is the passport, it looks more as a guarantee certificate.
Is there anyone who knows what is it?
Thank you
Francesco