A-1 Professional Benz and Beemer in Anaheim, CA is a great place to buy used parts. They are a used car lot, wrecking yard, service and repair facility.
They have a warehouse that'll knock your socks off with parts from the floor to the ceiling on pallets.
My dad bought a nearly new steering box from a 1989 560 SEL that was totalled in wreck for his W126.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".