John George SWANSTON [1879-c.1935]

In my efforts to unravel the social circle of my grandfather Charles Warren from the names of the people who attended his funeral or sent wreaths, I've had difficulty identifying this person because of differences in the spelling of his surname and also the date of his death. Carl Smith describes him as a marine engineer, which seems right as we can find him in the Jurors Lists of 1909-11 as Foreman at the Taikoo Dockyard. There is a John George Swanston listed at the DBS in 1887 which would probably mean that he was born in Hong Kong. Carl Smith records his funeral at St John's but puts his age as 86 and the year of his death as 1938, whereas he must have been 56. I couldn't at first find him in Patricia Lim's record of cemetery inscriptions because his inscription is recorded there as John George Swanton and the year of his death as 1935. Carl Smith records his wife as "Mona" which matches the name of his wife on the same grave. In her book, Patricia Lim records Sergeant John  Swanston of the Hong Kong Police who died in 1891 and lies next to his five children none of whom survived beyond the age of five, according to the gravestone. She mentions a single surviving son who attended the DBS in 1887 without naming him. This must be the John George Swanston I am looking for, named after his father.