I am glad to be able to assist you.Usually I cant assist anyone so it is good to be able to do so.
Now as to your points:
Harriet.Her maiden name was Cocksworth and she came from Thearne/Woodmansey.She married a man named Rhodes but he died and she was left with one daughter.She then married George Fallowfield who had been a mariner but settled in Hull to be a grocer.They married at Holy Trinity which is the largest parish church in England.
Christopher John Fallowfield of Chapel Lane in 1839.He was the uncle of the other CJ Fallowfield.He was born in 1839 whereas your CJ was born in 1856.I know when the uncle died but I cant lay my hands on the date just at present.
The Canadian records were interesting.They state that CJ the younger was living in Canada at the time his sons joined up.Is this in accord with your records or perhpas his sons just said that to avoid any difficulties because I note that each says he was living at the same address as they were but one lived in Montreal and the other in Saskatoon.I checked the Commonwealth War Graves site and neither of the brothers appeared to have died in the wars.