Bushwacker,
Thanks for the advice. Mine is a 1984 23' CC. That could very well be the problem I am having. The bow seems to be lower while on the trailer which could be trapping air towards the back of the tank. I am thinking the reason why I was smelling fuel fumes in the bilge through hull vents the following day is because, I had the fuel all the way up the fill line and probably a slightly loose fitting towards the top of the fill cap? Great idea on cutting and installing an access plate in the inner liner adjacent to the fuel vent/hose fitting, brillant!!
Thanks