Parts? lots of sources:
First, the M-B Classic Center. Just email your chassis number to Tom Hanson.
thomas dot hanson at mbusa dot com
Also, Miller's Mercedes-Benz:
millermbz.com
And of course, the M-B type clubs, such as:
www.mercedesheritage.com
By the way, aren't those brakes actually ATE (Teves) brakes with American standard SAE parts? ATE actually bought license to manufacture Bendix brakes for the older M-B cars.
I had a 1958 M-B, and could get most all the brake parts (cylinders, pads, etc.) from my local NAPA.
Tom