I'm curious how much the Aussie 580K differed from the USA version. The 580K was built in Iowa? Or was it? A good friend demoed both the 580K and G at the same time. He remembers there was $20,000 dollars difference between the tractors. He pointed out the flat glass on the G, higher ground clearance, taller tires, lower price, and a whole lot less moulded plastic, and upholstery on the Italian? built G. The K was to his thinking, not worth the extra money.
Dearly loved, and cared for, passed from first owner, to next door neighbor, who also cares for it, at 3000 hours, it's tired! My K has almost 5000 hours, The interior upholstery is very tired, everything electrical has failed, and been replaced at least once. Function wise, it is still going strong. I love my K but recognise that all that plastic moulded interior luxury was never intended for VT winters. At -20 F that plastic shatters like glass. Carpet, and fluffy stuff won't hold up in weather, and holds moisture encouraging mildew, and rust.
I notice you have a different hoe, I wonder how much else is different.