Hi there , I’ve bought a 66 Sprite and tacho doesn’t work , the car has been changed to neg earth so I’ve read a couple of forums and change the two bits over in the clock and cut and swapped the wires on the loop but when reading it said replace metal strip back on loop, there wasn’t one on mine or a nut iv found a nut but don’t know what the metal strip is, have any of you good people got any ideas please.