You can get a new catalytic converter and new shackles and springs. Reach out to Cruiser Outfitters or any of the other great MUD vendors that sell suspension parts. Magnaflow makes the only California-specific catalytic converter that I know of. The replacement has to have the Executive Order number to pass smog. The spring mount/hanger is riveted to the frame. If its not heavily pitted or rusted through, just wire-wheel it and coat with something to neutralize the rust. I'm not a fan of painting rusty parts, but you can do that if you want to or put some corrosionx or fluid film to protect the bare metal. Also, the steering dampener can be purchased new aftermarket (Dobinson's or OME or Rancho, etc., etc.). The splash shield under the radiator and pulleys I think is not available new, so you can clean up and paint as well. Its alot of remove, clean and recoat or replace with most of the parts on these trucks... They are 40+ years old...