Over the past few years the needle position on my fuel gauge, when the tank is brimmed, has dropped from the full position on the gauge to a point somewhat lower down. I'd like to get rid of the various yellow paint pen dots I've built up to tell me roughly how much fuel is in the tank!

The tank ...

Hi Folks, I'm replacing the speedo cable on my Series 3 (petrol) with a genuine unit and whilst I can work out what seems to be a suitable route for the cable, I'm wondering if anyone can describe the way these were fitted at the factory please?
Pics woud be handy too.
Thanks in anticipation.