I think this is William's death, age 76, in 1981, MMN McLean., Glasgow, Martha St.
From his marriage to Christina, in Gretna, in 1934, his parents are Alexander, Stone Mason & Jean McLean.
There is a marriage of an Alexander to a Jeanie McLean, 1902, Port of Menteith
I think this may be him on the 1911 census, age 6, in Dumbarton with mother, Jane, 32, & siblings, Jane, 7, & James, 3. (correction, Not them)
Added:
This is them: 1911, Port of Menteith, Alexander, 38, Mary, 37, William, 5, Sarah J.F. 8, Mary McGregor, 7. Alexander, born Sutherland, Mary, Kincardineshire, William, Port of Menteith, Sarah, Whiteinch, Mary, Kincardineshire.
Alexander remarried, 1908 to Mary McGregor, Dornoch.
Out of interest, Christina's parents were James Armstrong (Shepherd) & Helen McKenzie, married 1903 Blair Atholl, Perthshire.
Added:
Christina was born, Wemyss, Fife, 1911