Hi Maverik. I know that is a very long time since your post but I have a problem. I need to replace my master cylinder but TRW no longer produce them and I already try bearmarch but they don't work. So I remember that I can fit the old model the ntc4991 from TRW (still available) and blank the two extra ports. Did your adaption of the NTC4991 (blank of the two port) worked ok? What was the result in the long run?