From my knowledge of repairing PC monitors, I know that focus can be retuned from inside the monitor. Most PC equipment is produced the same at the factory (with the exception of 110v/240v and 50/60Hz), it is merely configured differently via a process of 'trimming', which any computer engineer worth their salt can adjust.

The main problem you would encounter with PC monitors is the refresh rate of the screen (measured in Hertz), which is affected by the mains supply. As NZ is 240v/50hz, which is the same as the UK, it really should just be a case of minor adjustments by a technician.

Dont try this at home folks as getting a shock from the points on a tube will really not be a lot of fun! Some monitors have up to 33,000volts running through them (called High Tension, much like a car has High Tension leads for spark plugs) which will probably throw you a good few feet across the room. I know a man who clipped the end of a tube with his wedding ring and the ring sliced his finger completely off!

Anyway, thats my lesson on PC's over and done with!