Let me lead off by saying this isn't mine & I have no interest in the outcome but thought some of y'all might be keen to get one of these. Unfortunately I find myself skint at the moment or I would be bidding on it myself & not posting this
I just saw on ebay there is a Is-Was for sale. I am not sure what Subsims policy is on external links (and I am to lazy to look it up) but you can find it if you search for "Antique Navy Submarine Attack Course Finder".