I pm'ed Duane but will also ask the general group. Who has restored a front bench seat and a rear CONVERTIBLE seat? It's a 1970. I am sure it is burlap, layer of jute, cotton batting, and the cover on the front. The rear is a molded "bun", cotton, cover... Anyway... I am now completely restoring both seats. This is for comfort, as it's going into a Skylark that will be driven quite a bit. So, no need for originality. I am figuring burlap, jute, foam (either 1-2" foam), and a layer of batting... However, this may be wrong and maybe there's a better solution? Thank you!
I have a friend that has done a lot of these. He uses the cheapest fake fur from a fabric shop to cover the springs and a molded foam under the covers: https://www.legendaryautointeriors.com/product/66-70-gm-a-body-split-bench-foam-see-notes/ Shop around for the best price and correct application. No need for burlap, jute, horsehair, etc