I'm pretty sure
Pilot Xenon has Xenon conversion kits for the car. I got a set from them which (after a bit of work on their part, since the default wiring was wrong, and my high-beams and lo-beams got swapped, and switching the two switch-wires resulted in exactly the same behaviour) finally works the way it should.
I'm guessing it's based on your current lightbulbs what kit you'd need, but it'd never hurt to ask. Bonus on this is that if they start harassing you on the Xenon, you just pull the plug out, switch back to the halogen bulbs and you're done. Also this kit has an EU approval (which most kits in the US do not have) which may save you from problems down the road.
As to diverting the beams due to the driving on the other side of the road... Maybe someone in Australia can answer that. If I recall correctly they drive on the same side as the UK people, and there have been Mustangs built specifically for the Australian market. The manual doesn't state anything about aligning the horizontal direction of the beam other then 'it's not possible'. So I doubt the regular head-lights would assist in that.
Then again, I'm more at home with the newer models, so I'm not sure at all about the 1972 ones... Hope this helps a bit.
Anyone in the uk change their headlights? 
