Nissan Patrol Master Cylinder

[Neilzimbabwe]

I have a 1991 Nissan Patrol 2.8 ltr European specs, assembled in Spain vehicle.
The brake master is non functional. It is a girling unit (british). To look at the unit you have to break off a plastic cap which is attached to the end of the master unit and sits inside the servo when assembled.
Any body have a suggestion for a replacement unit that would just bolt on ?