After my orginal front disc brake system tried to kill me about 5 years ago but lucky only broke my left arm and thumb, while recovering I decided to upgrade my whole front brake system, I went for a full Grimaca system, 12" floating disc, calipa, master cylinder and SS brake line, its one of the best improvement I have done to my brake system, one finger operation if I want, brakes that work the way they should, yes its not orginal looking but it looks better, stops great without effort.
Even doing a resleeve and better pads and SS line it still wouldn't work as good as what I am now running, I would never go back to the original front disc brake system, my life is more important than keeping it orginal looking but then my whole Norton hasn't been orginal since the early 80s, having modern brakes on a old bike is so good.
Keeping your brakes orginal is all good back in the 70s, but having your brakes let you down when your life depends on them.
Ashley