Jim,
Not sure if this is one of those parts made from "unobtanium" or not. I helped a friend redo the engine compartment on his 250 SL, and we did run into some issues with the piping, even consulting with our local (and US) guru Dave Gallon. BUt Dave G is an excellent source of information about parts, especially the hard to find ones. He could at least tell you "nope they don't make it any more" or some other options.
Another option (if you have the original pipe as a model) is to go to a machine or metal shop to see if you can get one fabricated. They are not a hugely complex piece, you just need the correct diameter, length and bends.