Fuel gauge issue is normally fixed by cleaning the contacts on the sender unit with fine sand paper etc, as long as the wiring is ok (and the float is still sealed) that should do the trick. When all else fails double check and clean all earth wires, maybe add some more.
I don't know if I should be flattered or insulted Mik Anyway, here are a couple of pics. Rims are dusty and dirty but could still use a polish, tire tread is 40-60%. Pics are of two wheels only but I have 4 all in similar condition. Cheers, Levey.