[ShaneHobson]

Completed switch mod to easily pull engine codes by using the (redundant) fog lights switch.

Replaced MAF with spare which was cleaned & resoldered.

Drove 250km round trip with no errors codes from MAF.

Still getting errors 12 & 37
12 Starter Switch or Circuit
37 Oxygen Sensor (No. 2, Left Side, On SVX)

So it looks like I've solved the MAF error.

I've booked an automotive locksmith to swap the ignition switch tomorrow with my spare (he's familiar with correct procedure to remove the headless bolts).
That should cure error 12, perhaps.

That just leaves the oxy sensor. I'll clear the codes and go for another drive just in case it needed to blow some crap of the pipes (vainly hopeful).