Sadly, my options are limited here. There's not so many engines about here, and they are generally not well known.
I have an option of a 4.2l ABZ engine, but not sure if it will direct fit. I see it shares some components with the ABH. It's a working engine, from a 2000model A8.
Am still awaiting more info on compatibility.
There are more engine options in germany, but carriage costs to the UK would likely make them non viable.
Maybe I should just scrap the car?
Which is a shame, as the rest of the car is generally in good shape. And I am most of the way through the hard work on the car, having stripped the engine out.
An ABH 4.2 is available, minus the heads. So I may look into that.
Watch this space.
And if anyone is aware of a good engine coming available, either 3.6 or 4.2, then let me know.