Completed the fuel tank today by wiring the fuel sender. I'd previously cut down the plastic which surrounds the terminals so they could be bent over for additional clearance. It was just a case of cutting the wire to length and fitting a couple of female spade terminals and a short length of heat shrink to tidy it up.
The 11/16 written on the top of the tank is to remind me what size spanner fits the top fuel fitting just down the side. I've made marks like this in a few places and found it saves time hunting through different sizes spanners/sockets etc. until you find the one you need, especially when the fitting is partly obscured and not easy to see.