Just spoke to Brad Newman at Paspaley and fuel from Kuri Bay is now no problem. Just order and pay well in advance, particularly for unleaded which is 200L drums only.
Check with Paspayley in Darwin, but unless things have changed this year, you shouldn’t need to order or share diesel. They have a fuel dumb barge in the bay that you tie up to and Paspayley staff will come out to pump as much as you need on board. But its always a good idea to give them plenty of notice about when you are likely to be there and how many litres you think you will need.