Hi again Jacky
... ooh, yes, .... you definitely need to keep reading those (NZ) newspapers !
Have just found a whole lot more about Benjamin and his family ... which doesn't necessarily pop up when you search on "Benjamin/ Ben, O'Neill".

Will add details in following posts.
Back to electoral rolls though ... I searched 1925 :
** Benjamin (farmer) and Lucy (married) were at Dennett Street, Avon Electorate (same as for 1928 listing).
** Walter O'NEILL (farmer) / Elizabeth (married) were at Brookside (Ellesmere roll).
** Joseph George O'NEILL of Cass, surfaceman, and Dorothy O'NEILL, married were on the Hurunui Electoral roll :
So not very interesting ... or helpful to the "cause".