1986 SJ - Brake master cylinder

I have never had to replace one of these on any SJ/Jimny I have owned but I have been asked countless times about getting one that fits and works. It would appear that there are different sizes etc. and unsuitable aftermarket variants out there. 

Does anyone have any experience and recommendations before I go off and learn for myself how to get the correct one. 

P.S. brand new, not used.

 

Sorry never had any problems with them. But i have bought a service kit for these once, but never had to use it on the SJ. But when my daughters horse carriage had a stuck brake master i found that the gaskets and rings for the SJ fit the carriage master spot on.
It was an easy job to get all the oxydation out and make it shiny and fit the new seals..

Anyways my contacts here in the suzuki club should have no problem finding the correct part number, but you can do that as well I guess?

Thanks 

As a further question, the master cylinder I have is 13/16 which I assume is the "bore" of the cylinder. I can find a few SJ that are 7/8 (which is, of course, 14/16). Now apart from "1/16", is there any actual difference and do you think they are interchangeable?
 

I had an issue with my Jimny master cylinder and had a nightmare trying to find a suitable replacement or the correct parts to rebuild it. There seemed to be more parts available for SJs than Jimnys. I bought a rebuild kit that looked right but was the wrong size.
The bore affects the mechanical advantage of the system. Switching to a larger bore will give you less pedal travel but require more force on the pedal to achieve an equivalent braking force at the wheels.