I work in a bodyshop on the side and if you have the body soda blaster you still have to sand the body as the soda leaves it too smooth for the paint to grab and it will peel , and as old as that vehicle is I would have it chemically stripped but be forwarned as it is going to have to be able to be lifted ( which might cause some twisting of the body we built wooden braces to prevent this ) and sandblasting like was said before warps and blowthru soft panels and sometimes leaves the surface rough and grainy .