Ken, I've been unable at this stage to contact the owner...

I have ascertained a couple of things. It has a modified version of the head made for Strombergs (from Lotus Europa Twin Cams, possibly etc) done by Ken Duclos in America. He's made up a twin-Weber manifold to adapt to those heads after machining off the Stromberg cast-in manifold.

The present owner is at least the second Australian owner, he bought it from a collector in Sydney. I saw the car both at his place in the urban part of Alice Springs and also out on this rural property, it gets around a bit.