Originally Posted by Screwdriva

We're partly to blame for the problem. So many of us buy cheap aftermarket parts from suppliers like URO, further demonstrating to Mercedes Benz that demand for quality spares is falling.

I'm in the midst of restoring my 43 year old W115 240D and have been able source 99% of the parts needed from Mercedes Benz US/ EU dealers with only 3 exceptions:

1) Engine stabilizing strut (sourced from a Mercedes specialist in Germany)
2) Heater Blower Motor (Not available anywhere)
3) Radiator (Behr unit Not available anywhere)

Source your parts from the dealer if you can. And if you can't contact their classic parts departments to log your request for that part. They track requests and remanufacture accordingly.