Well what can you say about a brake master cylinder? it is cast iron, it is new, it fits in the hole and I am sure it will work, however.... my original cylinder had the popular remote reservoir adaptor screwed in the large threaded hole at the back, so I thought I would simply unscrew from my old one and screw into the new one, but the threads were not the same! so I had to drill and tap the new plug , so which was correct? the one in my car or the one I bought on ebay?
Maybe it will just remain one the great mysteries of the universe, - who really cares about these reviews anyway?