[SS427]

Danny,
Here is what I had collected some 30 years ago and to the best of my memory. The first shot is a 1/4" and a 1/8" original lanyard cable clips removed from Chevelles back in the late 70's.

The next photo is of a supposed NOS piece that I obtained MANY years ago alongside a readily available replacement hardware store for $0.03 each item. The hardware store clip is more white and not as opaque.

As far as where/how they mount, the next photo shows what I most commonly see on Chevelles for the hold down screw. Joe D's black survivor LS6 used the same screw as you showed.

The next photo is of a survivor Arlington car that I have in the shop. I have never seen this type of rivet used before on a Chevelle. The lanyards are original as is most of the car and would like to know if anyone else has seen this before.

Lastly, this is one of two ways I always see Baltimore cables attached. Sometimes clips are used while most of the other times the cable is simply mounted to the bolt.