Standard AN10 swivel 90 fitting. (Earls or Areoquipe sells these all over the world.)
You should be able to get them in Germany too. Just ask around. (Heck, the shipping from San Diego to Germany is going to be more than the cost of the fitting by the time he pays the taxes and fees.)
If that will not work, try hydraulic fittings. They are the same flare and sizes and will work fine. (Besides, they are steel, and should be less prone to crack, but any of these fittings with crack if you over tighten them.)
Snug with no leaks is the rule on AN/flare fittings of this type. (Don't ask me how many I've busted on hydraulic systems in the middle of the night at 10f... Not fun at all, so you get a very good idea of just how tight is right, and then STOP turning the dang wrench....

)