Was at downer as of a few days ago, it’s been spotted at various Sendiks as of late, and it’s on the shelves at places like festival outside of the city. Yes, in the city it may be hard to find, but elsewhere it’s around. I’m not saying your OP is impossible, just highly unlikely. People paid $5-10 dollars a bottle for KBS.
Just giving some trade advice, don’t take it the wrong way. KBS and BBPt5 have a much higher trade value than those CW beers. The two you’re looking for were brewery only or extremely hard to find, where the CW beers can be found on shelves currently. Potentially you could trade quantity of CW for a bottle or two of your ISO, but you’ll most likely need to add some harder to find beers on your end.