I was not really surprised to see that this rifle now turned up for sale with Rock Island Auction, now with an estimate of $ 20,000 to $ 35,000.
While comparing it with the rifles in Mike and Steve's book I especially noticed the 4 of the "G40k" designation on the receiver of rifle V84 (the one that goes from auction to auction) has serifs, whereas originals don't have that. Additionally Mike and Steve's book list serials up to V83 being made and additionally V85 being made, but no documents speak of serial V84.
For others to see, this is the rifle at RIA:
https://www.rockislandauction.com/d...40k-experimentalprototype-bolt-action-carbine
Note the miscolorations around the markings..