[BaadAssGremlins] A 72 Matador Gas Gauge Question Again

I know I asked this question almost a year ago but I need my mermory refreshed. The one thing that makes me nuts is a non functioning gas gauge. The previous owner said it worked. It was his wifes car and she is not what you would call a rocket scientist by any means. I doubt that she ever put more than 20$ worth of gas in it at a time. I filled it up and the gas gauge went from 1/4 to 1/2 and then 2 weeks later it read empty. I drive it locally but not far and run it from time to time to keep the battery full. When I got the car back from the new simulated vinyl top repair the shop owner said the gage read empty. I said I know. I figred itn was time to put some gas in it. I was warming the engine up to take it to get some gas when it died. Out of gas. I put 2 gallons in it and it started right up. I put 20$ in gas in it and now the gauge reads almost 1/4 which should be about right for the amount of gas I put in it. I am getting the car back from some minor repairs today. I had the ground and sender wires cleaned and the sender wire grounded. It pegged the gauge. Someone said somthing about maybe a problem with the float being bad and when the tank is filled over half it sinks? Are these floats replacable? if so where can I get one. I would prefer to get a new sender like I did with both my Hornets though due to the price of labor only to find out a float replacement did not work and I flushed the money down the drain.
"Doc"