I'm ignoring my caliper dilemma for the mo!
Tonight I mounted the handbrake and plates in there final position. Just tacked in place for now but I love it in this position for impromptu reverse handbrake turns! I have practiced it loads in the garage.
Right up against the drivers-side (marked passenger side just to confuse) tunnel rail.
With the gear stick in reverse there's still plenty of clearance.
Clears the the prop nicely too.