Thanks for the help guys!
Still struggling to find a loom, by the sounds of it finding an 8v is going to be the best bet. They seem in high demand. Every breaker I contact has either already sold it, or someone else is interested blah blah.
On the engine front, I will probably end up doing a 2L conversion, and get the head ported and polished. Gearbox could do with a refurb, but don't have the cash for that. So plan is, for now. Pull the engine, new loom in, 2L bottom end on. Repaint the engine bay, engine back in. Happy days.
Just need to find a loom....!!!