The limit for RS was 5 bottles, 10 bottles for HS. However, after the allocations ended they had additional bottles left and they are currently for sale with no limit. My guess is that there are at least 8,000 bottles, but probably less than 10,000, if that's any help.
It should have been rare but it seems either they brewed some extras or not everyone maxed it out. I personally value it as a great limited availability shelf beer. I would think you would be able to snag one for great shelf stouts from the Midwest. Heck I might trade a couple bottles with you for some great Midwest shelf stouts. I will look out for your iso thread.