As I just bought the bike, and was doing project planning, I wanted to know my options, Having now found the master cylinder welded from a previous accident, the decision was easy , I just ordered a PS16 to replace the original in the photo, so that with new callipers and discs, things should go pretty well, thanks for all your help, New P4-30 Calipers are on the way, now I just need to find the mounting brackets. All original parts are heading for catalogued storage.