Dropped bucking bar in leading edge

Any ideas on how to fix the 'outie' caused by dropping the bucking bar into the leading edge. It's hard to see in the photo, but it's to the right of the reflection of the guilty bucking bar.

I did that twice....

I did that twice with a tungsten bar. Both were too big to massage, one had some cracking. Both times I drilled it to a 1/2" hole and made a four rivet well radiused and edged square patch over the hole, minding the edge distances, with 4 426-3's out of the same thickness as the parent. Once was fuse bottom, once similar to yours. Fifteen minute diversion, move on. Even I have to go looking for them now that it's painted. Aggravating when it happened....hardest part was dimpling the parent metal in place. Good luck, ymmv.

I had the same thing happen in my fuel tank. I tell people that I have extra range fuel tanks as a result!

I thought about making it an innie and filling it with something; maybe even drilling a hole dimpling it and setting a solid rivet; but I plan to polish my plane, so these repairs didn't suit me.

I tried a variety of remedies, but the one that worked was to first carve out a male form out of oak to fit the inside. My buddy held this form tightly against the inside of the tank, and I used the flush rivet set on the outie with really low air pressure and gave it a few seconds worth of taps while moving the rivet gun in an arc to match the arc of the leading edge. I gradually increased the pressure until I was happy with the results. Since the metal stretched, it would never go back to the way it was, but mine is good enough that you have to really look for it to see it now.