11th: Rev Archibald TURNBULL

A helpful lady on the Rootsweb India list pointed out that the family had some baptisms on the IGI (which I'd not thought to check, thinking that the dates were too recent, given that Scottish extracted records mostly stop at 1875).
That netted baptisms for all bar Mary of the known children, and added an 1896 Betty into the family.
Then another web search netted an article about the Turnbull School in Darjeeling, which was built in memory of the Rev. Archibald TURNBULL in 1906 after his death (1905).
The article also includes a photo, reproduced here:

with the implication that it was taken at the opening of the Scotch Kirk (St Columba's) in Darjeeling, 15th May 1894