So in the end I bought the Facet Posi-Flo pump. We'll see if it's man enough for the job. I'm mounting it at the front under the tank. Can anyone advise the best place to take the live feed from? The instructions mention a relay but I haven't bought one; do I need one?

Ideally they want to be wired on a pump relay so it stops if the engine stops in an accident. You can also get oil pressure switches so the pump runs when the pressure light is out it gives the same safety. Mineis wired straight off the ignition and has been for 31 years no problem.

Thanks Snoopy. I thought that's how I'd done it before. It was in the film and distant past though. Do you have an inline fuse on yours?

As mineis along side the gearbox it is direct to the ignition feed with no fuse as is the electronic ignition module. Under the front true fuel tank I would put a  5 or 8 amp fuse in line.

try this

with a relay for safety cut out

That's excellent davydoff! Thank you. For this weekend to get it started up I'll just run a wire to an ignition fed fuse. I think evilsea is coming over with his carb balancer to help. I'll save all the electrical buggering around for tidy up time once it's on the road. Where would be the best place to buy the relay and push button?