Let's be clear.... anything can be repaired.... But at what cost/time/materials? Your car has serious rust throughout the midsection, literally from dogleg across to dogleg. I have never seen one that bad personally. I have a friend nearby here in Canada who just disposed of a 240 with less than half of the damage yours is showing. Don't panic, he has two others to restore. The point being that IF you have deep pockets to replace the doglegs, surrounding sheet metal, door sills, rocker panels, floor pans, frame rails, seat anchors, and probably numerous other areas of the unibody you MAY be able to restore the car. The biggest issue I see is that you have very little SOLID metal to weld onto! You literally will need to start welding metal from the roof down in order to have good steel to add the panels to! Reread the comments, look at the car objectively, look at the other restoration threads and see what people are starting from in comparison.... THEN decide where you want to go. I believe your best option has already been suggested in parting this car out and saving the best pieces for a restoration of a better frame. Best of luck!!