This is getting most bizarre - have found David Alexander's death:
21/5/1887 Royal Infirmary, Edinburgh - David Alexander 45 Agricultural Labourer, Army Pensioner - usual residence 6 Brown Street Lane (?)
Married 1st - Elizabeth -------- (left blank)
Married 2nd - Mary Malcolm, formerly Reeking (? - some of the writing is difficult to read)
Parents John Alexander, Gardener (deceased) and Susan Storrie(or Starrer? - hard to read) Alexander, formerly Scobie (deceased).
Died of Acute Pneumonia - informant was wife Mary Alexander.
I then looked for marriage to Mary Malcolm and found it 10 (?) January 1884 in Edinburgh - this time father is named as before, deceased, and mother Susan Alexander formerly Starrer (?), deceased.
Clearly the right man but his mother's details vary slightly from certificate to certificate. Presumably the 1st marriage shown to an Elizabeth should be Helen Turnbull but perhaps 2nd. wife didn't know precise details.
All the various documents involved in this saga indicate he was born 1839 to 1842.
His second wife was only 30 when they married so wonder if they had any children between 1884 and 1887.
Annette