Pulling the ABS fuse created some error codes

I looked at the wiring diagrams and my above assumptions are wrong. The OBD port does connect straight to the Ford ECU. I also tried a different scan tool in Ford mode and I was able to get it to connect; I guess that the other one wasn't good enough.

Therefore I should be able to implement a mode that goes straight into the Ford V8 ECU without going via the Gateway ECU as the T4.

Anyway, I have already gotten the Gateway ECU protocol working. These are the screenshots:-

V8 Gateway ECU

I think that the numbers for Revs and Coolant temp are a bit off, I need to re-check them.

X12 V8 Engine ECU (in T4 mode - via the Gateway ECU)

I haven't finished reverse engineering all the live data parameters (there are lots) yet. I will update when that's done.