Is there such a thing as a bolt-up dual-disc setup for CB500?

[ImagoX]

Wondering if anyone can recommend a bolt-up solution to add dual discs to a '71 CB500F? I like the look and setup of Randaak's new brake master cylinder (Model A: http://www.randakks.com/Brake%20Parts.htm), and figure if I'm increasing capacity I might as well look into also improving stopping time.

Question is: Are there any dual-disc setups that can be used in conjunction with the stock wheels? I do NOT want to swap wheels or perform extensive (possibly risky) modification to the hubs that may be beyind my skill level/tool availability.

Thanks... --M