Hi Brno!
I vaguely recall hearing this song before, although I am not sure because I am aware that some of these traditional songs borrow from each other in terms of melody, chord progression and the like. As a student of traditional songs, do you find that to be the case? Your posts often talk of the evolution of these traditional songs.
Your reference to Australia piqued my interest, and in particular the reference to the Western Plains. I had to look up where that is - it is an area immediately west of the Great Dividing Range in New South Wales (the state whose capital is Sydney). The Great Diving Range is a mountain range just in from the east coast of Australia and stretches the length of the east coast from top of the state of Queensland down through the state of New South Wales and into the state of Victoria. Dubbo is a city that is often associated with / central to the Western Plains area.
I listened to a few versions of ‘Across the Western Plains’ on YouTube after listening to your song.

What is the bass sounding instrument doing a solo at 2:55 in your song?
Andrew

Regards,
Andrew D
Adelaide, Sth Aust
Soundcloud: https://on.soundcloud.com/SQE4btVvNVkLq74e9
Youtube: https://www.youtube.com/@andrewoftheantipodes