Two Koberstein's immigrated from Guben Prussia in 1877

 Koberstein, Gustav Adolph (calculated birth year 1857) and Karl Friedrich Reinhold (calculated birth year 1855).

Here is the location for the only modern day Koberstein I have found in Australia.

I believe this may be the location of Howard Springs, however it is in Queensland, not Northern Territory.

Here is a reference to Koberstein in Australia:

Eighth Assembly First Session 10/13/98 Parliamentary Record No:11

I also rise tonight to speak about one of our Territorian retirees, George Fyson. George was born in Brisbane on 19 February 1935 and his family lived in the Brisbane suburb of New Farm. ...

In Darwin, George worked for Roy Barden and for Terry Irvine, both private chemists. Late in 1964, he took charge of AB Motors for his father-in-law, Ben Hingston. AB Motors was the forerunner to today’s Mitsubishi on the Stuart Highway and held the agencies for Chrysler cars, Kenworth trucks and Massey-Ferguson tractors. In 1970, Ben Hingston sold the business to Hans Koberstein, a former milkman and land developer from Howard Springs. George found himself in need of work and although his pharmacy skills were somewhat rusty, he was recruited by Spike Langsford, the Northern Territory Director of Health. After 3 months, he was appointed Chief Pharmacist and within 12 months he became the Director of Pharmaceutical Services.  ...

Another reference:

18. Howard Springs volunteer fire fighters Ralf Koberstein and Jim Fawcett