I made a template and cut the lower right side panel from some sheet. Next, I ran it through the E wheel using a PU upper wheel to put a bend in along the upper 3 inches so the panel rolls inward to meet with the upper panel.
Then I used the shrinker to bring the curve in so it follows the edge of the top panel, then planished with the E wheel using the steel upper wheel.
After some fitting and trimming, I tacked the panel in and checked suspension clearance under the car. All is good so I welded it up.