My 74 Z needs a master cylinder. Although everything works fine (no fade or spongy pedal yet) it's developed that patented leak between the cylinder and the booster. It's been nearly 40 years since I've gotten a replacement cylinder for anything so my question is what are the experiences with replacements? The picture of what Amazon sells looks much like factory original. While I like the idea of the stock look, it's hardly a deal breaker. I have a good used MC from a 74 that I dismantled nearly 30 years ago but I'm reluctant to go that route for something that critically important. What are the experiences?