Small update... some wiring parts arrived and picked up a white board to help me scribble down wiring stuff. It's been pretty handy 😀
According to the MegaSquirt manual, it's a pretty good idea to shield the TPS and trigger wires. So have been on the search for a flexible 2-core shielded cable, ended up deciding on a microphone cable from JayCar (part no. WB1530).
Terminated the shielding into it's own BLACK wire, this will grounded at the ECU end and left floating on the sensor end. The BLUE wire will be used for sensor return and the WHITE for sensor ground. The +5V/+12V wire will be run externally to the shield.