Fuel tank filler tube installation trouble

Progress update: No luck so far. I decided to order a new grommet, this time from DMT, and see if it works better. The old one was branded OER. This may not be the problem but before I damage something (or myself) I'll give the DMT seal a try and report back. I'm learning that my biggest hurdle in getting this car back together is no longer my skill level but the inconsistent quality of the restoration parts now available. Quite a change from the 1990's when I last worked on a classic Mopar.