Whats the best way to repair this seat?

The interior in my cabriolet is very good and original apart from this monstrosity!
I've found someone who can supply the cloth, i'm pretty good with a sewing machine, so i was going to remove the seat cover unpick the stitching and replace the panel using the damaged one as a template.
The problem is the filler / padding is damaged, it's the weird fiber stuff like shredded wheat?

any ideas??????

im doing the same with a set of seats the best is to buy a cheap one and use the stuffing(shreded wheat)lol.theres a set on here he dont want much for them.