I can't say definitively what it is, but the leg scales are not right to be a CDT. None of us are used to seeing russians that are that old and weathered, and I think that may be contributing to the uncertainty. Can we get some head on pics? We've now seen the top and bottom, but how about some head on pics?
Did I see this one while I was there, or was she one of the ones hidden in the night box? I don't recall any of your russians looking un-russian like in person.
Is she the mother of any of mine? Sometimes looking at the offspring can offer a clue too.
Russians have a large range and its possible that 68 years ago they were imported from an area that they are no longer imported from. This and the age might account for the different appearance.