See post #42, but briefly I did the open-heart surgery myself (that's what it felt like anyway) - replaced the 'IR cut filter' that was in front of the D200 sensor with a piece cut from Edmund Optics long pass filter material (750 nm).
So it 'sees' permanently in IR but the viewfinder view is normal. Luckily auto-focus is still spot on (as is the result of manual focus).
I was trying to remember how I did the false colour shots (it was around eight years ago), I think it involved swapping the blue and red channels in photoshop. I'll try to work it out again!
Great mine shots BTW.