I've kept my interest in FSU cameras alive though, and I just came a cross this on ebay:
http://cgi.ebay.com/Fed-Stereo-3-8-38mm-Stereo-lens-No-88-Museum-/230625525617?_trksid=p5197.m7&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D4%26po%3DLVI%26ps%3D63%26clkid%3D474164010811378830
According to sovietcams, total production for this camera was ~50 units, and this one has a lens with serial number 88, which seems pretty cool, but there's no way I'm paying that much for my humble collection, so just thought I'd let you guys know in case someone was interested!
If I'm breaking any rules by posting this link or anything, sorry
Oh, and no I'm not affiliated in any way with the ebay guy :P