I bought a used White White Lightening in "perfect condition" that had been shot and stored without cleaning. Bore was full of "fuzz" andd the seller disappeared. Cleaned it like you did and got to where I could see pitting. Spent a couple hours with JB Bore paste, smoothed it to where patches ran smooth and the pits appear clean. It now shoots about 2" at 100yds - so I think as
sabotloader said, it might be salvagable.
Certainely worth trying.