That is a relatively easy part to get, and repair. cjponyparts is where i got mine, about $26.00, and has a bigger and finer pickup screen, to keep out chunks of rust. You can play with the float bending it up or down, till you get your guage to read as you like when close to empty.
Hi,
If you add your location, it would be easier to recommend a vendor nearby, to save you turn-around time. Most all of the mustang vendors carry as good a quality as the other. Most all of them are, most likely, coming from an offshore mfg.
Good Luck