Thanks guys. I'll be working on it tomorrow, I'll see how we go.

Which actually reminds me I can't seem to work out where the fuel return is, there's something mounted on the firewall where 3 hoses meet and 1 runs from the back to the block, another to the second hard fuel line (next to the feed line on the body) and the third was attached to the carby. It's a little strange why it goes to the block

[EDIT] you can kinda see it in the background on the picture, with the smaller hoses running into it (not the coolant into the firewall for the heater).