It seems rather dramatic to seek a new loom when all you say you have damaged is the plug.
Surely its possible to find a breakers with a smashed car, cut the section of loom that goes to the ecu, then splice the new plug and cable onto your old loom with connectors.Its not as if this is a new car.
I will go look at my 1.8tdci Focus in the morning.
Incidentally, do you find your EGR gives a shushing noise at certain throttle openings? Mine always has.