Fuel gauge

I dont have a pic of it but its just a clip on steel tingy that carries the ground path over the rubber hose at the sender. If yours is missing you can make one with a short piece of wire and 2 gear screw clamps.
If yours was working the strap was there. Maybe its still there and just needs cleaner contact points.
There are some poorly built senders with plastic floats out there too.
If a saturated float is the problem the gauge pointer should still climb from its home position to the empty mark at switch on.