get a car loom from a carbed engined mk3, it won't have the engine loom, so that cuts a load out str8 away. You'll be building your own loom for the zetec anyway just using ignition lives, permanent lives and fuel pump feeds etc.

then get a haynes for mk3-4 escy, get all the insulation tape off the loom and take out what you don't need. takes ages to split a loom though, cos of all the shared earths and things you'll need to cut.

then just re-tape it, or if you're that concerned about the weight, just use some small zip ties to keep the loom in loom form. Use one about every 8 inches and around joins, junctions etc and if all the wires are uniform length and clean of all the sticky stuff, it'll be fine.