These are instructions submitted by Tom Young for reproducing the retainers that keep the seatbelts in place on the bottom of the front seats.
In the picture below the two extreme left ones are the original loops. The four on the right are the reproductions. The bottom picture also shows the material that they were made from. It is 1 inch wide canvas material. These loops measure 1 inch wide by 6 inches, which are folded in half and sewn together as original with one hole for the screw. The second picture is a close up of the sewing thread pattern.
The loops are held down by the outer screw of the bumper pads on the rearmost part of the front seat bottoms.