Did you eliminate the connector for the ignition switch as a problem? The contacts in the connector sometimes go bad.

Man sounds like your facing the same battles i am with my brat, but i rather enjoy what i am doing to the brat, Rust well i'm fixing to cut out the bed and form/cut a piece of sheet metal to replace it, just cut out all the rust under the doors and will be welding in some 4x2 steel tube/fram, just replaced the whole fuel system new gas tank, lines rebuilt cars and fuel pump. On my way home my bumper fell off LOL so had to fix that one at work today, just got all the lights wired up corretly. whole center consol got rippred out from previous owner,and most the body panels are missing 80% of the bolts to hold them on, and i could go on and on but hey when i'm done it will be a pimp a** ride with a 6 inch lift and some 29" mudders so just remember for as bad as it is, it can allways be worse, thats what i allways say just hang in there and you'll get it all rolling