I have no direct experience with this, however after having wired engine swaps both from the ground up and also modifying an existing loom I'd do it from the ground up any day. Then you know exactly what connects to what, can remove any useless crap, can route it nicely and basically can do it properly. Modifying an existing loom can often lead to mysterious wires crossing back and forth across the engine bay.
So I'd recommend stripping the AW11 loom, labelling it all up, plugging it into your motor then running everything where it needs to go. Then shortening/extending to suit. For a sweet as finished product.
Hen