Thank you Donna
I do believe that the family in the 1871 cesus is the right family, John snr being Christian(a)'s son. The family in the 1881 census is more likely than the family I had residing in Cumberland.
The age at buriel for John Cain(e) is right.

When my husband's grandfather (Oscar Steele) visited the Isle of Man during 1917 where he met and married his wife Dorothy Hulme, he was visiting a great uncle descended from his Cain relatives (presumably from Christiana's second marriage to Thomas Cain, thus a half brother of Oscar's grandfather Richard Steele).
My assumption is that Oscar's relatives lived in or near the town Dorothy is from. In the 1901 census Dorothy is listed with her grandmother, Mary Field, and aunts at Conchan IOM. Her father , Leonard Hulme, married Dorothy's Aunty Maud Field in Douglas abt 1902. Frank Leonard Hulme was a town commisioner in Laxey circ 1907-8, Dorothy was listed on Oscar's next of kin as living in Overdale, Garwick, IOM in 1917.

Therefore I believe the Cain family lived in this area in the early 1900's.

I have enough details about Dorothy's family - she was born in Manchester (and I have family bible entries that date back to 1776). Here I am focusing on the Cain/Steele connection.