New position sensor back in after some delay getting all three mountings screws back in. Longer arms and less shaky hand would have helped

. Plugged new unit back into loom and before final button up checked via OBD2 hookup that pedal operated throttle. Much joy when it did, opening to its reported maximum of 75% as before. Cable tied sensor cable as little higher to reduce possibility of throttle foot disturbing it, given MMC modified orientation.
Interesting to note replacement sensor, according to moulding marks, was from same batch as OE on my 2018 car showing made in November 2017. Likely only 50/50 chance at best this will fix the issue but just going through the motions now.