I have just noticed your posting re "Those missing Hill's" I too have been looking for more information about James.
James is my great great grandfather on my maternal side of the family.
It would appear that he arrived in South Australian in 1848 with a wife named Jane Casly. She died approx 1853, I think that their were two of three children from the marriage. He then had seven children with a woman named Susan Lockman, Lock, Lowman or Lockley, the eldest who was William who was my great Grandfather. His daughter Mary Jane Hill was my grandmother. I have not be able to locate a marriage in South Australia for James and Susan.
All the Hill family lived in the Payneham area, a suburb of Adelaide. List of address vary from Marden, Marsden, and Campbelltown. I grew up in Adelaide, so I am very familiar with the area and names of the suburbs
You have much more information about the family than I do. Are you a member of the extended Hill family?
Cheers Jo I now live in Brisbane.