Hi , Steve,
Love the project and what you achieved thus far ..
Please feel free to field any questions my way and at the very least can offer Elsawin wiring diagram pages.
I am going to ask if you have the CAN gateway module , the central electrics module and the convenience module aswell as the ECU's you mentioned before . Also what fuel tank / pump / level sender do you have ? .
The canbus can then be long-programmed to remove unused items .
Oh , and was the donor car manual or auto ?
Cheers