Hi Jonty,
In the event that this proves to be your Benjamin GREGG (and I think the reference to Cumberland is a strong link) I found several more articles where he received a mention:
Daily Southern Cross, 5 October 1872, Page 1.PERSONAL
BENJAMIN GREGG, from Victoria.— Anyone knowing his whereabouts please write to Wm. Gooch, News-agent, Ballarat.
http://www.rootschat.com/links/0rjz/ Included only for elimination purposes.
Tuapeka Times, 17 September 1892, Page 3.WARDEN'S COURT.
Friday, 16th September, 1892.
(Before J. S, Clendon, Esq., E.M.)
OCCUPATION LICENSE.
APPLICATIONS.
The following applications were granted:-
Kong Kee and others: Extended claim of six acres, Havelock Flat.
Ah Schoon and another: Water-race (four heads) from Tuapeka River.
W. E. S. Knight: Water-race (four beads) from Barber's Creek, Waipori.
Benjamin GREGG: Water-race (one head) from Canton Creek, Waipori.
http://www.rootschat.com/links/0rk0/Tuapeka Times, 15 January 1898, Page 3.TUAPEKA COUNTY COUNCIL.
CHARITABLE AID.
The secretary of the Otago Benevolent Institution Trustees wrote stating that John M'Bean would be admitted to the institution, and that Benjamin GREGG was granted 4s a week for three months.
http://www.rootschat.com/links/0rjy/Spades