The old York compressors are fine as far as R134a is concerned per se (higher working pressure for instance) .... but are not acceptable these days due to size, weight, and lack of smoothness... they were much like Harley 45degree engines... huge masses moving back and forth... you can tell by the massive steel support structure used to hold them.... my parts 79 wagon had one... They also had the advantage of having an oil sump... so they were not in the classification of the Delco Scotchyoke of being so prone to failure if your refrigerant was a little shy of perfect in moving the oil necessary for lubrication around the system.
The York had two cylinders.... the Delco has four ( and is also kin to the Harley example).... and most compressors today have six cylinders ( with the direction of travel and work changed to the longitudinal axis )... you can see the progression to smaller work per unit of crankturn and better hiding of the motion to minimize vibration.
If you bring your MB back to stock out of the factory I am sure you will be pleased with it.. remember first that air across the condensor is the primary limiting physics rule ...and that you will HAVE to clean out the evaporator... see DMorrison's thread about how dirty those can get over the years....