Made the mockup of the tank vent and tried Van's tool. Looked like it would be Ok, but turns out the nutplates for the fuel level sender interfered with the device. Plus it was almost impossible ot get the wrench on the tube nut inside. Tried several small changes and then quit to remove the fuel line that goes to the tank. This gave more room, but did not provide the answer.
Made my own wrench out of a 12 point box wrench with a slot cut in it to fit over the tube. This reduced the required rotation from 60 to 30 degrees. Ended up bending up the wire that was used on the wrench. Was not sure, but might have had it work once, still the nutplates.
After 3.5 hours just put a cleco in the box wrench and a safety line and managed to get it on the nut. Removed the cleco and just shoved the wrench with my thumb then wiggled it off into the tank and retreived it with the safety line. Got about 30 degrees of turn. Was not able to get the box wrench end back on. A neighbor showed up and he got the open ended on and got another 40 degrees. Got the box end on and got another 30 but had a very hard time getting the wrench off. Time to quit. The nut is still loose, more wonderful adventures tomorrow.
