F*** me, found it lol. You guys are gonna bend me over for this but I was checking some of the other fuses mentioned in that TGTT thread, came to the EFI one last. Prodded the wires running around the outside and one was loose, surely this was it? Poked it back in place, lo and behold the car fired up at once! Major thanks to everyone that helped, I really really appreciate it! Just relieved it was a simple fix, albeit as long as it took! Phew!