David, I see where you got your Robert Christian and wife Cath from, but can't understand why you hadn't found her surname when you have all the children's full names. [Mother: CATHARINE FARGHER]

His age given in censuses is very erratic:
1881 on Familysearch:
Robert CHRISTIAN Head M Male 48 Maughold, Isle of Man, England Mine Labourer (Lead)
Catherine CHRISTIAN Wife M Female 46 Arbory, Isle of Man, England
William Jos. CHRISTIAN Son U Male 23 German, Isle of Man, England Lead Miner
Thomas Hy. CHRISTIAN Son U Male 19 German, Isle of Man, England Tailor
Catherine Ann CHRISTIAN Daur Female 13 Patrick, Isle of Man, England General Serv (Dom)
John Evan CHRISTIAN Son Male 11 Patrick, Isle of Man, England Scholar
Elizabeth M. CHRISTIAN Daur Female 9 Patrick, Isle of Man, England Scholar
Edward A. CHRISTIAN Son Male 7 Patrick, Isle of Man, England Scholar

Source Information:
Dwelling East Foxdale Rd
Census Place Patrick, Isle of Man, Isle of Man
Family History Library Film 1342344
Public Records Office Reference RG11
Piece / Folio 5596 / 72
Page Number 21

In 1861 he was b.c.1827 Maughold which would be correct for Port-e-Vullen Robert. In 1871 b.c.1830, and in 1881 above b.c.1833. Cath was 29 in 1861 and 38 in 1871.

They married 1 NOV 1856 Kirk German (extracted record IGI) and as you know this will show the father's name and occupation.

Would you please let us know on the BB whether he was the Port-e-Vullen one?

Sue