Roof Skin Replacement....

Check the A-pillars for internal rust. Been there. Plug the bottoms and pour them full of Chassis Saver. and the drain them. Sometimes they are unrepairable and will need to be cut off and replaced. If that's the case there are times to replace the whole roof not just the skin. less welding , Weld the a-pillars right below the drip rail seam. Measure three times and weld once . Some I did I had to remove the drip rail due to rust under the skin. Good luck. Don't rush it and think it through. Plan your cuts on both cars.