I bet your jeep had the swing out spare tire carrier on it that bolts the passenger rear panel and latches to the drivers rear panel. That was a horrible choice locating the spare from jeep, it places too much stress on the panels when the carrier is opened and closed, and your pics show the results. I would not put the carrier back on and find another way to carry a spare, or don't carry one at all. Short of replacing or welding, I have taken a small cable across the back from panel to panel and tightened it up to bring the panels back into position. You have holes already on each side of you tailgate, you could have a tab welded to the gate and the panel and bolt the two together, early cj, tailgates were held shut this way. Don't feel too bad, it is very common to see this. I was talking to a friend who recently got a 94 wrangler and I was showing him common rust areas, and was going to show him how the tailgate will separate from the panels because of the tire carrier, his had already separated, but his was bad, it was separated from the top almost all the way down.
