Here are some photos of the plastic fuel tank installation.
A marine tank was used, and fitted with a 24V fuel sender unit I found online. It wasn't quite matched to the original gauge in the dash, a full tank showed as half full on the gauge, but it's better than having to guess!
The main reason for doing this is the fact that the tank is around 400litres, which is a lot to try and keep full to stop condensation forming. When we got the vehicle we had no end of trouble trying to get the tank cleaned out, it was full of watery sandy mess. We started using Jerry cans fitted with the kind of adaptor used for running generators, but it is annoying not knowing how much fuel is in the can and having to stop after 10 miles to put a new can on, just in case.
The tank fitted where it is means minimum modification work is required. We held it in place with CVRT stowage straps and Land Rover strap staples. You could very easily replace the aluminium plate we removed and go back to running the original tank if required.
Chris