So achieved my goal of having everything in the car running by yesterday.....almost. Thwarted at the 11th hour (literally) by what appears to be a malfunctioning immobilizer. Engine turned over nicely on the starter, no codes yet and no leaks anywhere. Discovered after a few attempts at cranking that the fuel lines were around the wrong way, swapped them back and then.... nothing. Completely dead electrically. Battery has charge and all the earth points appear to be solid so must be the alarm system but will have another look over everything today after work and see what's what. I took the fuse out of the fuel pump before pulling the lines, any chance this has triggered something in the immobilzer circuit to shit itself? Seems to be the only thing that changed between starting and not starting. Have swapped the fuse with another one just in case but no dice so far.