Here's something for all of you to look at and take into consideration. I was changing brake lines, hoses and hardware on my GT and figure to clean the MC and booster at the same time. I wire wheeled the MC cap and what I thought was just surface rust wasn't, (check pic). I called OGTS and was told by Dennis, they have exhausted all sources, including Opel for the MC caps, there are non available. BUT any German make car with the ATE MC will work, they all have the same threads. Also any 5/16 fuel hose will work for the reseroir to MC hose.