I used a Zetec from a 1993 Mondeo. The engine loom is separate and connects to the body loom with 3 oval 12-point plugs. The engine loom is pretty self-sufficient, you can just connect the power, feed the fuel pump and try starting the engine. That said, if you use the Mondeo engine loom, the ECU ends up somewhere near the radiator. So I unloomed it and changed the layout.
I traced all the wires in the loom to the ECU, here's the result:
http://fridge.pov.lt/~alga/zetec/Mondeo-ECU-pinout.pdf
The subloom at the injectors, TPS, CAM was badly weathered, so I rebuilt it. Getting the terminal pins for the plugs was not easy. I found them at Würth, already crimped to pieces of wire ready for soldering.