I had the same problem on my truck, float filled and sank
However being on a farm with a PO box no one ships to up in Canada where delivery times would take forever I used copper from an old stove top boiler pot and pounded out a new float from scratch, seems to be working well so far.
Related note, in my 50 truck the gas gauge in the dash is suppose to be a for a 0-30 ohm sender, and my sender is still perfect 0-30, but through the years the gauge drifted and was now expecting 0-4x ohms for full scale, turns out if you put the sender and gauge together on the ground with wire clips to the battery you can crack the tiny adjustment nuts on the back of the gauge and tweak it back to reading full when the sender just reaches the top. There is lots of adjustment range, you could prob match up an original instrument gauge with many aftermarket senders.
