I finally removed the fixed cup. I tried the Sheldon's method with the 5/8th nut/bolt and broke the bolt. As I didn't need to preserve the pitted cup, I decided to cut into the cup at the surface where it meets the BB shell with a dremel tool and cutting wheel. That removed the friction between the two surfaces. I was then able to remove the cup quite easily. I refer to use the Phil Wood retaining rings and a Shimano Cartridge BB anyway, so damaging the cup is not an issue for me. Again, thanks all for your very valuable tips.