[MP&C]

Originally the seams were butted tight and welded. I cut through the middle of that seam and dressed each side as best I could, and the panels had a tendency to cave in, especially now given the gap, so I needed them to pull out slightly. I started with the horizontal weld that goes from behind the door on the lower patch. A profile template was made based on the profile just behind the door. As the template was moved rearward, the clamp innards (only what is shown in the pic) was hooked behind the two panels, and pulled out grasping onto the threads until the panels matched the profile template. Then while maintaining the tension, the template was set aside, grabbed the Mig torch and tacked. Checked again with the template, planishing as needed. Moved about an inch or so and repeat. Once the horizontal weld met up with the vertical weld seam, the same process was used on the vertical seam, using the 60" rule as a profile gauge across the weld seam. By holding the rule at an angle to the panel, it relaxes and gravity helps it conform to the crown of the panel. Using the clamp innards again, pulled the two panels until the crown looked consistent across the rule.. then tacked, verified, and planished each.

So it was just finger powered tool, pulling and maintaining tension while the two halves aligned.