Passing through Mansfield on the way to Woodspoint today.
I was given a tank without fittings. I made a plate that attached to the original pump housing which worked brilliant. Used easy to get parts. I drilled a hole in the pump housing using the template on the Safari tank site for the Bent Berg tank. I then cut a plate out of aluminium to match the pump housing screws etc. I bought an angled barb that had the 1/8 BSP tapered (I think it is). I bought another female fitting with the same thread so I could cut a 'nut' off the end of it. I tapped a thread in the alum plate with a 1/8 tap, screwed the barb in then the nut on the back of it. Use Performance Plus sealer (cheap from Supercheap etc. Bit hard for you in Mansfield but the local parts stores might have it). I made a gasket then fitted along with pump housing. The hole in the housing will allow the back of the barb/nut to fit. This worked brilliant and faultlessly.
Source the fitting instructions for the 70* tank for more info they are out there.
You run a hose between the two with a quick disconnect.
When you run the vent pipe, keep it high. Don't go down then back up again. What happens is you get an air lock by way of fuel in the vent pipe.