I bought mine from Willcox Corvette 800-588-3883. They do not have an up to date website, but if you call they are very helpful, and have great prices.
The installation kit comes with hog rings and clips (looks like a paper clip with issues). I assumed the clips were to connect the wires in the covering and the seat foam and the hog rings attached the fabric at the edges. My seats have been reupholstered before so I don't have a guide.If you are missing some of the hog rings from the install kit, email me your address and I’ll send you a bunch no charge on Monday firstname.lastname@example.org .
Your post mentioned clips, but I don’t know of any clips used to install the 79-82 seat covers. The rods that pass through the cover ring direct to the wire in the seat foam. I went to our shop this morning and took an original seat back apart.
You just need hog rings. Hog rings for the inner wires at the seams/channels, and hog rings at the seat cover edge.
I have had many a car seat under my belt, I used to own a custom shop that did auto interiors back in the late 70's - early 80'S.
What do you think about using plastic wire ties for the inner wires? You know the kind used to bundle wires. They are flexible and pretty strong. Occurred to me this might be a simple solution.
I am punting the clips - they have exceeded my knowledge and expertise. Hog rings I understand.