Could also be the stop solenoid failed, cam lobes in the hp pump do wear out so it doesn’t pump at high enough pressures to run ( more so running on red, that doesn’t have so many additives)
If you are smelling petrol, there is either a leak or trouble in the float chamber, have you remembered to put a little oil in the damper if it’s an su carburettor?
If the body is earthed properly to the chassis and battery, I suspect there is a connection that has been crimped onto insulation rather than bare wire in your circuit
Bracket usually found on plant trailers, to stop overrun brake cables from dragging on the road, I suspect the tyre caught it, and flicked it up under your vehicle