Check out any of the sixteen Oil Pump components enlisted.
With two applications this Clip 101235600 is the most specified part.
Parts such as the Oil Pump: Clip, O-ring, Oil Pump Assy, Clip (214-13164-00) are included in the Cw50 2004 5ww1 Italy 1c5ww-300e2 Oil Pump parts fiche.