Hi everyone,
While Alexander shows a grocer in 1881, I can't see him in Scotland in 1871, with a similar occupation. I am guessing he married Eleanor Elizabeth Cunnington (Carrington, per 1881?) in 1875, Richmond, Surrey? You may need to apply for this certificate, to get his father's name and occupation.
There is an Alexander, c. 1844, brother to George in the 1871 census. Their mother, Lilas, is living with them also. His birth is probably the 1842 one, born to William Skene and Lilas Cowie in Turriff. He does "disappear" after that census, so it could be him.

hume24
That Skene family (headed by George) looks to have moved to Gamrie, Banffshire by 1881. No Alexander with them.