I doubt that it could be made from a Kiev mount lens. I've never seen or heard of 3k before, but OTOH, there was a lot of wierdness going on in Soviet optics in the day's after they snagged Zeiss. The ad claims it was made by KMZ, which actually makes some sense... My guess is that it's Soviet production of wartime bits produced at Jena. I don't know if the wartime Sonnars in LTM were made in collapsible or not, but even if not, whose to say the parts for a number of prototypes didn't exist?
It also wouldn't surprise me if the lens was just too complex (or viewed that way) to be made with Soviet QC (which was at it's best then, but I digress...).
If I had the coin to spare, I'd snag it just out of curiosity. If it worked, so much the better - be a fun lens, for giggles if nothing else, to hang on the CL... 😱
Edit: The fact that the seller takes paypal inclines me to think that, at the least, _he_ believes what he writes. Just that little bit less likely to be an outright scam from him.
William