Again ,jorose and shellyesq, you have given me much to think about.
In 1900 Agnes gives her year of arrival as 1864 and 1910 as 1868. Not sure what to make of that but it is strange that 1864 coincides with the death of the James Bennallack in Tavistock and 1868 is the year in which she married Thomas King. My instinct is that James never reached America. I shall have to invest in a certificate before I go much further. The possibility that Agnes was "adopted" by the Bennallacks does have some credibility.
I am satisfied that the James of California is not mine. His place of origin is shown as Redruth, West Cornwall, an area from which my James's family migrated in 1800 before settling in Devon.
William of Gilpin, Colorado is much more interesting. He is my James's cousin. More than that, his family is known to have been in Michigan around the time of Agnes's marriage to Thomas Henry King. William's brother, Ralph, (and James's cousin), married in Negaunee, MI in 1872 and James,'s uncle, Thomas, died in Ely, Marquette, MI in 1878. Neither place is particularly close to Eagle River or Clifton, but a possibility exists that William was the witness although it is strange it should be him, having to come from Colorado.
In 1870 John King is shown as aged 0 years which would be consistent with birth in February 1870. I believe the later record is in error.