I've just found a little more on this chap. It pays to keep worrying at these problem individuals.
Walter the eldest son was born in the July quarter of 77. His birth registered as Walter Stedman Chivers - before the marriage of the parents in December.
At marriage John gives his age as 26 a discrepancy with later census which give a YOB as 1859. If born in 59, he would have been only about 18 at marriage. His wife 10 years older. Perhaps he lied at time of marriage as he did not have parental consent.
Ive found him on the 1911 census age 52 - an inpatient at an asylum described as Lunatic since aged 51.
Still no closer to establishing his parents.