Gasoline smell/may need fuel tank

[bigeasy1]

I have a strong smell of gasoline whenever I fill the tank in my 23 Tsunami.This only happens when I fill it all the way.I never let it overflow and always stop pumping the gas at the first sign of any gurgling.
The smell is very strong coming from the hull vents up front.I had the boat on the trailer next to my deck,when we got the strong odor of gas coming from the vents.
Fortunately,when I restored the boat,I made the bottom of the front hatch removable,in case I ever had to access the the bilge area in the front.
When I pulled the panel up,exposing the bare inner hull and keel strip I didn't find any liquid gasoline,but when I rubbed my finger along the surface it was slippery and smelled of gasoline.I also lifted up the motor box in the stern(it's an I/O),to check the bilge,but didn't find any gasoline.There was some bilge water with an iridescent sheen,but I think that was more from a small oil leak from a previously leaking oil pressure sender.

I ended up mixing a batch of bilge cleaner and water and gave the entire bilge from front to bath a good cleaning.No odors since.
I'm hoping that it's from just a leaking fill or vent hose,or the fuel sending unit on top of the tank.All these hoses were new and alcohol resistant and installed when I did the resto three years ago.The sending unit was new as well,all hoses were double clamped.
This doesn't happen if I don't fill the tank all the way.
I put 15 gallons in when it was low and I got no odor.It only happens when I try and fill it.This leaves my to believe that It's either a minute leak from a loose hose connection,or the sending unit and may leak a tiny amount when the fuel reaches that height in the tank.

It's the original aluminum 1974 tank 55 gallon tank and was made in Hialeah Fl.It had some very tiny pitted spots on the corners,and surfaces,but we checked them extremely carefully,and even did our own pressure test on the tank with a couple pounds of pressure which held overnight.
I coated the tank with some interlux epoxy barrier coat to keep any future water away from the aluminum itself to stop any future corrosion.I only boat fresh water.

So, my three questions.
(***has anyone had any similar experience,or any thoughts on the issue?)
(***Who makes aluminum tanks in the New England area, if It ends up being the tank.)
(***does anyone make a sending unit that lasts longer than a year?

I checked out the plastic tanks but none fit my space,so it looks like I'd need an aluminum one built to the same size as the one I have in place already.
Any idea of the price range? I hope! it's not the tank.
I'm hoping to get back up to the boat(6 hours away)in early October to take up the tank hatch and check it out.

Here's a pic of the original tank,back in place with the new hoses and sending unit.