Someone cut one out from a fox and installed it in their classic. Wasn't just cut and weld, if I remember correctly. I did a quick google and found nothing.

 

On top of what was said here, I always grab a few of the paper towels they have at the pump, and use them under the nozzle. If it does happen to try to overflow, it helps to stop it, and if not, I leave it there, and use it to cover the tip of the nozzle when I remove it. This way, nothing drips on the paint.

 

On StangFix a guy cuts filler necks and installs a small section with an opening the size of the nozzle similar to later model cars.

 

Thanks for the suggestions. Broke a rib and the weather has been pretty crappy, so I haven't driven it enough to need gas again. I'm going to try the 1 o'clock position thing and not stuff it in all the way and see how it goes.

Last time, it was like washing my car with gasoline (on top of my fresh paint!). Well, the tail light panel anyway.

As a fallback, I'll fill it up with 5 gallon gas cans like I had to before it was drivable.