[Shiny]

Made some progress... mostly good, learned some stuff.

The Harbor Freight stud welder worked great - better than I expected so I went for it. It pulled a little out before it pulled out a chunk so I attached a second and continued with the slide hammer:



Comparing the DS to the damaged side, there was a well-defined fold line that I decided to focus on. The distortion is obvious on the damaged side:



So I welded a 3rd stud and alternated with a slide hammer and a pick hammer inside the trunk to start restoring the fold:



Got enough movement before the 3 studs pulled out that I started to hammer directly on the fold. I held a right-angled dolly on the fold as I flattened and kept using the pick hammer:

[Shiny]

This is where I stopped. The folds are defined better and the crease is pretty flat:



This is enough to feel OK about moving to the real challenge of the "#2" crease: