Desmond, you wrote:

"My great grandfather Francis had 5 brothers and sisters (James William, Amelia, Christian, Thomas and Walter) but I have not been able to track down any of these in later censuses"

If you have a subscription to Ancestry, you'll find a tree which has been compiled by a direct descendant of Francis's sister, Christian Shimmin b 1846. There's a nice photo of someone who was, I believe, a second cousin of your mother ( there's no information at all on the wife or descendants of Francis b 1852, though, so the tree-compiler is probably unaware of what became of Francis.) I'm sure you'll find it interesting ---- the family of one of Christian's daughters moved to Canada.

Jean C