Well, it IS more a resto-mod than a restoration, but it makes economic sense to have more modern and reliable parts on the platform. After all, this car is going to do serious professional work, rather than (say for example) be trailered to the New Zealand equivalent of Pebble Beach. Moreover, I can only imagine the difficulty, not to mention expense, of finding 1959-era correct parts--on the other side of the planet, no less-- to bring it to exactly as it was when delivered to the original operator.
Sure looks good, doesn't it?