Trying to figure out the hole patterns and sizes for the various rear vertical engine tin grommets and what goes through each hole.
I know the orange tin is from my 73 and the black tin year is not known.
Have measured the hole sizes and marked on tin.
So far I know:
A. main positive battery cable on passenger side (23mm)

B. back up light and secondary solenoid lead on the drivers side (16mm)

Other unidentified holes are 16mm, 23mm, 23.5mm, 27mm in size

This is interesting to me Bruce. I have not seen a side by side comparison of the rear tin variations over the model years. There must be more than just these two, such as a 75-76 version with a pass side hole for the EGR tubing.

The two 7mm holes are for a special zip tie with a drive pin clamp which holds the battery+ cable (Is that a machine screw/cable clamp shown in your orange piece?)

The ignition harness branch to the starter goes through hole "C", not "B"

These pics from my 74 2.0L (looks to be identical to your black one above), as originally from the factory (never removed before I removed them for these pics)

I was hoping you would have some input. I do see you have the D shaped grommet that goes on the inside edge against the engine case. Do you know what goes through it?
Bruce

Also note they dropped one of the screw holes where the vertical tin attaches to the cylinder tins.

Nothing goes through that D-grommet, or the others. I think the grommets are just rubber hole fillers and that this rear tin piece is used for other applications such as Vanagon, VW T4s, where something goes through those other holes