First the particulars: 1973 spider, refurb'd 3 years ago.
It has started to leak gas, after a fillup. The first time it happened, I did not pay close enough attention and had filled up into the tube.

After that, the car will leak even when filled to below the filler tube. The dripping does stop, so I believe the problem is not in the tank itself. The dripping is coming off from the frame, under the gas cap and not the tank. I am trying to determine: 1) the filler tube became loose or 2) something else has been messed up. I appreciate all ideas.
Jim