..../... a huge number of Mercedes parts now - some of which may be even re-badged by MB, who knows!?.../...
The vendors that supply to M-B Classic [perhaps to Daimler as well] are not openly visible - a company privacy issue of course.
But, be assured, there is
not a little corner in the M-B factory in Sindelfingen where a group of emplyees, alongside and intermingled with the current S-class, E-class etc. production lines, busy themselves with making parts for a vehicle type where production ceased some 50yrs ago...
That is just
not the way it works in the auto industry...
Mercedes Classic is a separate entity, and they order and sell parts for older types of Mercedes made by their network of chosen vendors. Production orders are for parts made according to the M-B specifications and drawings (which of course M-B Classic have full rights and access to). Thus, those parts can be duly marked with the M-B star and label ! The associated quality control is one reason for price differences.