I'll have to rip into the console to test the brake switch - the seat
switch operates as designed.

So - it seems that it is either:

1. the brake switch NOT fully disengaging and shorting the ingnition
2. the ignition switch shorted inside
3. the PTO switch shorted inside
4. cracked/broken insulation on a wire - SOMEWHERE - causing an
ignition ground condition

I won't have time to dive into these properly for a few days.

Thanks everyone for your views to this problem!

Eric Tonks wrote:
When checking the safety switches, some may be normally open, others
may be
normally closed and open when operated so that they don't short the
ignition
to ground to kill the engine.