Gee, what a familiar site! My seats look just as bad. I think the person that owned my '84 before me beat it to heck. I threw on some slip covers for a while but they looked too tacky for me. I've been looking for replacement seats online and in junkyards to no avail. I got a decent price from a local shop for custom recovering, complete with new foam and embroidery, so I think that's what I'm going to do with mine.
I also need new carpeting and door panels. I've already replaced most of the dash and console components. So many things were missing or altered on my poor Baby. The clips in the dash that hold the screws to the dash bezels in place were missing so the guy just drilled new holes. It was a mess!
I found a box laying under the passenger seat and I plugged it into a harness that was just hanging inside the dash. I now have lights inside when I open the doors! I'm still trying to figure out how to hook up the rear defrost wires.
Good luck with the seats. And, have fun with your Vette!
Debbie