The picture on the left shows the two front bolts which attach the straps, which in turn hold the tank in place. On the right, we see the fuel line which screws into the front of the tank.
I had to squirt a little WD-40 on the screws and leave it over night. But after I did that, these nuts--which had seen 55 years of weather--came off with almost no effort. The bolts, shown on the right, are captive in the car body. The gas gauge sensor (aka the “sender”) had a permanently attached wire. I just cut the wire, and will run a completely new wire later.
All of the assorted hardware used to attach the tank is shown in these two pictures. 1) The tank. 2) Sender wire. 3) Supporting strap (2 each). 4) The neck. 5) Neck strap and screw. 6) Reenforcing bracket, lock-washer and nut (4 each).