I have redone a number of those seats.. You can get the replacement pad for the bottom and back.. Not to much money.. Often the frame and a couple springs will be broken and need some welding and replacing some springs from an another old seat.. or replace the whole spring system on the bottom.. The back part may well also be broken but its usaly the frame and not the springs so can usaly be welded and reinforsed so it will not happen again.. New covers are easy to come by.. The last ones I did I redid the springs, new pads back and bottom., New covers on the front seats, head rest and arm rest.. About 800 bucks to do it like new..

Ken