I have been trying to buy the H exhaust piece that replaces the collector box for my '87 R65. I prefer the one-piece version that Max BMW says they sell, made in Germany. But I can't get any answer from them about delivery timeframe. I know there is one by EnDuralast from Euromotoelectric that is 3 pieces and a bit more money. Does anyone have experience or tips to share about getting and/or installing either one of these? thanks.