The tank I was working on had been damaged when someone tried to loosen the threaded safety/filter screen from the inside of the filler neck. When they were prying around they bent the brass filler neck, all but rendering the tank wrecked. I decided to try fixing it. Started with a good fine thread cap. Turned up a spud and threaded it to just screw into the cap. Then threaded a ring that just fit the spud... Then I bought a cheap C-clamp and tacked the ring to the clamp... Marked the ring and sawed out two segments... Test fit against the spud Then gently worked my way around the damaged tank filler neck and pushed it back into shape. All back to normal. Cut new leather gasket for the cap and tested it for fit. Good to go. It'll get flipped around and mounted at the rear of this car evenually. https://www.jalopyjournal.com/forum/threads/1950s-tube-frame-sports-car.993579/