2166 864 :Front door window regulator - right side
2166 865 :Front door window regulator - left side
Numbers assigned for castings, stampings, etc. were taken from the same list as part numbers. Thus are no duplicate numbers out there where where, for example, part number 1234 567 is used for the casting number for the cast centre bar on a grille and used a second time for a part number for a complete outside rear view mirror.
Each casting, stamping,nut, bolt, screw in a part has a unique part number. And the whole unit is given a unique part number. Parts books list whole unit parts, plus individual parts sch as nuts, bolts, screws. The only individual part numbers that may appear in a parts book is for a repair kit - water pump repair package with impeller, body gaskets, shaft & bearing, seal & washer.