With our privacy laws,it's hard to find more recent info.
However,you could search family trees and perhaps connect with one of their descendents.If you put in Charles and his wife Emily and their important dates,you may find some related folks.
Do you have or want the many passenger lists that are available here on Ancestry of their many travels?
The latest date I saw was in 1928 when Charles returned from Argentina via New York.He stated he was going home to Saanichton on Vancouver Island.He also said that he first was in Canada in 1892.I don't see that record but maybe he came with his parents or another relative.
There are passenger lists for a William Henstock and others.Do you think they are related?
One pasesenger list for Charles and family stated they were passing through Canada on their way to New Zealand.
It looks like his wife was born in the Falkland Islands.