Hi George,
A few years ago I ordered the NT aboriginal communities data from the NT Department of Infrastructure, Planning and Logistics. I paid about $130 for data covering about 2/3 of the NT. I can share that data with you, but it doesn't cover the whole territory.
You can get a quote by emailing here:
Land...@nt.gov.auAlso, the NatMap 250K dataset has most communities (
https://data.gov.au/dataset/ds-ga-a05f7892-ecbd-7506-e044-00144fdd4fa6/details?q=Natmap%20250k%20vector). It's a starting dataset that's free at least. But it's old data so you'll definitely need to check names against the atlas you linked to.
Cheers,
Maia