Looks like there is plenty of meat left on the disc and the flywheel and PP look to be in fairly good shape, a little hard to tell until it's derusted.
As long as the disc isn't oil soaked I'd just clean wash it good a make sure none of the springs are damaged. You can clean it up with some 180-220 grit paper.
I'd do the same with the PP and FW. Wash them good wire brush the rust, make sure nothing is loose or worn then use some paper to remove the rust. I'd use an Arkansas stone with some oil to clean up the surface.
Denny Graham
Sandwich, IL
