Not your typical Fuel Gauge problem

I recently purchased a Gen2 2008. Among the problems I have repaired due to neglect and lack of maintenance, I am now coming across a problem with my fuel gauge that I find unique to me and hopefully just a result of this poor car being abandoned for such a long time.

The history I know, as per Carfax. In its most recent times, 3 years, it has been passed through the dealer auction system four times, prior to that it had three legitimate owners, so technically I purchased a ho .. lol

Regardless, like a good pimp I am now taking car of her. On to the problem ..

The gas gauge drains quickly. When I brought it home and took it for its first drive after servicing it, it had 2 bars on the gauge, so I went to fill it. It took .7 gallons of fuel. Odd yes, but I have owned Toyota products with bad canisters, etc and thought I would be chasing down another emissions problem. That short fill though sent the gauge back to reading fuel, so I thought it was a stuck float. I began driving it.

3 days later at around 205 miles, it was back to just under half a tank, 2 bulbs under, so being cautious I refilled again, this time I hit 4.7 gallons. Now I began to think there is a problem with the gauge. Since that last fill, only my second tank, I decided to stretch it based on what the vehicle "should" be doing based on my driving style. Well I chickened out, because the gauge ran down to 1 blinking bulb around 180, I pushed on to 264, based on where I fill each time. This time it took 6.29 gallons, so I continue to avg about 42mpg so far.

So this long story to ask whether or not these gauges or the fuel sender fail in this fashion normally. Or is this just a symptom of lack of use. I have already re calibrated the fuel gauge and no change. Either way, if it has no detrimental effect on vehicle operations, I will simply track my mileage closely until I can dial in a more reliable mpg.