It was a couple of years ago now, so I can't remember precisely how I found out about it, but I think I stumbled across the offer on the Bruichladdich website somewhere. I went to check this before replying to you, but their official website appears to have changed significantly since I was last there.
Will the Port Charlotte differ from regular Laddie simply by introducing more heavily peated malt? Or are they re-configuring the stills (do they have a rectifier?) in order to produce a heavier spirit? Perhaps they have identified a different wood regime for the maturatin?