Just a couple of items:

If you need to lubricate the filler hose, use engine oil instead of Vaseline. Vaseline can and will attack rubber. The worst thing you will get with the engine oil is a bit of smoke out of the exhaust.

The picture of the gas tank you took to show the access plate to the filler neck is already showing that the access plate has been removed.

That extra hole forward of the filler neck is for one of the vent hoses coming up to the evaporator tank from the gas tank. If you don't have the tank and don't plan on putting it in, then fill this hole as it is a good entry point for fumes etc. Also check for a second hole that is either to the front or back of that filler tube. That's for the second vent hose, again cap it if you aren't putting the vent hose in.

FWIW

Enrique

Originally posted by EScanlon

The picture of the gas tank you took to show the access plate to the filler neck is already showing that the access plate has been removed.

Right. Now I'm trying to ascertain if and where the access plate was or should be, since there was nothing to remove there on my car. I'll look closely for mounting holes tomorrow.

Originally posted by EScanlon

That extra hole forward of the filler neck is for one of the vent hoses coming up to the evaporator tank from the gas tank. If you don't have the tank and don't plan on putting it in, then fill this hole as it is a good entry point for fumes etc. Also check for a second hole that is either to the front or back of that filler tube. That's for the second vent hose, again cap it if you aren't putting the vent hose in.

Yup, that's what it is. There are two holes there near the filler neck. One had the single included vent hose just dumping out below the wheel well, and the other is empty. As noted by Carl Beck in another thread on this site, this car did not have a vent system, but most of the holes, etc. for the system were included, since Datsun did start putting the vent systems in after the first month or two of production. I couldn't retrofit a vent system even if I wanted to unless I purchased another gas tank, since the connections for the system are not on my tank. I'll certainly plug the unused hole, and seal up the vent pipe in its hole when I put it back. Don't want to breath those gas fumes!