Rick,
The "C" style clips you are after are correct for the cover you are trying to install, not hog rings. The part number you at Carters is correct, I have the clips as well. I do classic and antique auto/truck upholstery and glass, 30+ years. Do be careful when installing the clips not to cut the seat cover fabric. Use a tack hammer to install if you have available ...... this will save your fingers. Without getting into a book here on installing the cover, fit your cover over the seat springs and batting, centering the cover and checking the fit. If all looks good, start from the front center of the cover working outward 2 or 3 clips at a time spacing clips about 2 - 3 inches apart alternating right to left, and front to back. I have these clips in stock at our shop if needed. Our website is www.aglassenterprise.com glad to help out anytime for all of your restoration needs.
restoman57