If you can get the Car COMPLETLY apart ( Yes STRIPPED )and cleaned.. then use Anti-corrosion on ALL electrical plugs and components.. with EVERY slide and Bolt coming apart to lube and check.. Engine, trans and Suspension.. Fuel System .. ALL of it..
This is beyond the capacity of normal humans.. So Sorry to say, I think it's a Parts Car..
Sell the Parts QUICK before they rust beyond repair..