I think there is pictures in this one:
Replaced delivery valve seals and..... W124 300D
Concerning the above Thread. When the side Cover is removed at the top of the area where the Gasket Seals you can see the Barrel Alighment Pins and the Holes and where the Metal has been staked over to keep the Pins from moving out. Sometimes if the Element Barrel has not been lined up with the Slot when the Delivery Valve holder is tightened that pin gest pushed out past the staked area.
If that happend you can see that that Pin is not as deep inside the hole as the rest of the Pins.
Worst cases. The Pin gets bent or the Housing cracks.
OM606. 910 possible delivery valve issue
post #10
1987 300d injection pump issue