Since I am due for an Etest in june and the individual relays for the previously mentioned supplier are backorder, I have decided to buy a used RCM like this one:

http://www.ebay.com/itm/98-99-00-MERCEDES-W210-E-CLASS-FUSE-BOX-RELAY-PANEL-MC0303-/230953153931?pt=Motors_Car_Truck_Parts_Accessories&hash=item35c5e1758b&vxp=mtr
The part# is 210 540 00 72

The transplant is successfull and the price is right!