I am related to the above two John's, who are cousins. Both joined the South African Constabulary in 1901, one died in 1902 from illness and the other went on to complete his service.
I cannot find any trace at the moment of John Ogilvy Gair Born 1881's return to Scotland so he may have gone on elsewhere.
On the WWW there are suggestions he went to Canada so I am looking for anyone with any info they are willing to share. Of course the favour would be repaid in kind with info I may have.