Rear tailight area ground points.
 

The front of the car is DONE!
I moved to the back yesterday.
I rebuilt the Euro Fog Light (Bulb holder was shot.)
When installing the rear bumper shocks (right side), I noticed 3-4 ground wires attached to a brass connector.

(Simular situation on the left.)

It appears from the way the wires bend that they connect to the lower bolt on the bracket for the bumper shock. Except that it appears that it should go on the end of the bolt after it goes thru the nut welded on the frame. I put it there and screwed on a brass nut to hold it in place.

I'm almost certain that this is the right point.
My uncertanty is that there are many sole purpose ground points on the car so it's quite possible it is supposed to go somewhere else.
Can anyone confirm?
Sorry don't have a picture.

Not sure on the SC but on an early car, the rear light housing ground is a ring terminal that goes under the rear bumper bracket fixing bolt. just make sure the bolt, washer, terminal and threads are clean. check with a MM to ensure a good connection. The ground can go anywhere on the body as long as there is a good contact.