Just spoken with Tony, Thanks for the recommendation Simon.
I am not 100% familiar with the insides of the fuel tank on the petrols (only been inside 1 previously)
This thread is probably all your garage should need pointing towards
http://www.the75andztclub.co.uk/foru...ad.php?t=58832
As said above, the fuel tank does not need dropping on these cars to get access to the internals of the fuel tank - it can all be accessed from underneath the back seat.
There is also a post on another thread which suggests fuel could be moved from one side to the other when the fuel filter starts to separate, which could explain your funny fuel gauge readings, before the failure to start (
http://www.the75andztclub.co.uk/foru...4&postcount=10)
Hope you get sorted soon, but as discussed on the phone I am afraid I can't talk your garage through the job as I am not familiar with the inner workings of the petrol fuel tank, but am happy to come and have a look at this problem if your garage doesn't get anywhere with this.
(This web page should give a rough idea of what the parts inside the tank are laid out like :
http://www.rimmerbros.co.uk/Item--i-GRID001965, but lists the orange clip as no longer available)
Best of luck
Chris