The rivets are pretty soft. Just keep the drill straight and work slowly. You can choose to drill all the way through, or you can stop just short, and use pliers to crush the inside of the rivet, then press it through the fender hole. To the right, you can see a rivet where I used the second method: drill almost through, then crush with pliers and extract.
First, disassemble the tank, then remove the horn. Next, take a ball peen hammer and your choice of block or dolly. Carefully tap out the dents being careful not to go too far. The result is to the left. You can see the dents are gone. The remaining marks are paint defects from the truss strikes. I will take care of those with other paint work later.
After that, the fenders were ready to come out of the bath. You can see they look a bit better. Give them a good rinse and wipe down to remove any remaining Oxalic formula. These fenders cleaned up moderately well, but still need some paint clean up, which will be taken care of later.
To the left you can really see the parts of the fenders sheltered from the elements. They appear much cleaner because they were not exposed. I will work later to blend the fenders together and make the weathered parts better looking. The goal is to maintain a "vintage" or "relic" look, but make it more presentable, smooth, and rust resistant.