https://en.wikipedia.org/wiki/New_So...les_Contingent
I believe it was attributed to being a "bring back" from the New South Wales Contingent.
"The New South Wales Contingent served in Sudan with British forces as part of the Suakin Expedition in 1885. Consisting of an infantry battalion, an artillery battery, and a small field ambulance detachment, it departed from Sydney on 3 March 1885. Arriving at Suakin on 29 March it ultimately saw little action, being involved in a minor action at Tamai on 3 April, and another at Takdul on 6 May. However, with the British deciding to abandon the campaign it re-embarked on 17 May and returned to Sydney on 19 June 1885, where it was disbanded. The New South Wales Contingent was the first military contingent to be raised and deployed overseas by an Australian colony."
I have attached an image of a "1885 N.S.W Soudan Contingent Lapel Badge."
https://www.1rar.asn.au/1-rar-history/1885-sudan/
Hard to tell but the blade decoration does look to have a "Gumnut" look to it.