Where is the pitting? The only place you need to be concerned about functionally is in the travel area of the fork, where tube slides through the seal. Other than that minor pitting is cosmetic, and is commonly found under the headlight ears of that bike (I had one).
Aside from that a good set of used forks/tubes is your best bet. You might have better luck finding a complete set of forks vs. just the tubes for your particular forks. I don't know how compatible the CB500 forks are for example with later model CB550 or even CB750 forks, which are all 35mm but might have different internals. The later forks might even be a little better, but not likely by much.
You don't want to bother rechroming - it's not just 'chrome' - its a hardened chrome surface as these are hydraulic cylinders, not shiny fenders.
