If I was in LA I would certainly call Jens http://www.krusekontrol.com/
He has worked on a lot of Diezels and his communication and turnaround time is outstanding
But I do not think he is "authorized", so you could also contact Diezel directly for an authorized shop. Diezel has amazing customer service and will steer you in the irght direction
I just called Jens actually and he told me he can’t work on it. He told me to find someone authorized. Seems odd because he has worked on my Herbert before. Who knows, maybe he’s just busy. I know he can do it but maybe Peter told him to stop?