If you like it then YES you should pick up what you can!
I can't speak to whether it's out of production or not but I do know prices only go higher and the Anti's just keep getting their way all too often.
So you certainly want to stock up on any blend that you really like whenever your able.
Investment towards your future enjoyment and all.
I'm not sure if we're talking about the same Old Ironsides, but the one, made by Dan Tobacco, is surely not out of production. Of course i do know about the availability at your side of the Atlantic