A little more progress to report. I've had to rework the entire length of the recess that the rocker panel sits into at the outboard edge of the floor pan. The recess was not deep enough so I pounded on that for a good 30 minutes last night. I also could not leave the dimple in the center of the pan the way it was. It was about 3/8s out of level so I made a few small incisions and made it look right. Lots of wedges to cut and weld into place now. It is finally starting to look like the factory pan, well minus all that beautiful rust.