Somehow I managed to miss it, but William Buckley Gladstone is there after all!
He is the second son of Murray Gladstone of Manchester and Charlotte Augusta Hinde. Murray was a first cousin of WEG, his father Robert was younger brother to Sir John (WEG’s father). William Buckley Gladstone was born 5th April 1856, married 2nd December 1890 to Alicia Sidney Bayley and had 4 sons and 2 daughters.One of his sons died young. The surviving children were: Keith Steuart Murray b. 15 Nov 1891 William Neville Harbord b. 10 May 1894 Malcolm Ewart b. 29 Aug 1899 Daphne b. 9 May 1901 Pamela b. 16 April 1905
No subsequent generations are listed as this genealogy was published c. 1912. Hope this is useful. Peter