Gilbert was the third child of Fleming and Elizabeth and the first son. I am unsure as to where the name Gilbert originated at this time
Gilbert was born on the 20 March 1836 at Tingwall, Shetland, Scotland
After 1861, Gilbert left home and pursued a career as a Customs Officer for the government and he carried on with this career until his retirement.
In 1903 he wrote to his nephew, Fleming Robertson (son of his sister Grace), at Waianakarua, Otago, New Zealand. Copies of the original and transcription in following link.
By now, he was living at 153 Mayfield Road, Edinburgh. Gilbert never married.
Death 01 FEB 1915 • Edinburgh, Midlothian, Scotland