Steve,
Sorry - forgot to answer your question re: the death of William Divorty.
This is a difficult one. William had two first cousin's both named William (Divorty) and born within a year or two of each other.
I have found burial references but have not been able to absolutely attribute any to my 2 x gt grandfather William. William Divorty & Margaret were living in George Street, Aberdeen ref: 1871 census.
By 1891 Margaret was a widow and had move down to London to live with her son Robert and his family.
Thanks for all the details you have found for me - I've now been able to update my genealogy database
Chris