I love it when a plan comes together.
A year ago, tired of the horribly pin matrix plugs on mk1 fuse boxes, I rewired my car to use a CE2 fuse panel and harnesses. When it came time to fit glow-plugs in, I ran the heavy wire to the Z1 plug on the fuse box, connected the wire that was attached to the coil to the coolant temp sender, and the only thing I had to modify was the plug for dash lights so I could take a glow plug light signal from the fuse box (pin U1/8 didn't have a wire on it before). Simple.
I bet there aren't too many 1.5 diesels out there running on hacked apart 16valve engine harnesses.