You mentioned being a newbie at the beginning of this thread. Well, I've been "doing family history research" for about ten years, as a serious hobby, and I have to say, this particular family constellation --John, Caroline, Charles, etc.-- is the toughest mid-19th century conundrum I've encountered to date. I do think that there are a few civil registrations to purchase, as well as the probate item that I mentioned...and you know, even then, we might not crack this nut.
I'd really like to know what those people were doing in Canada in the 1850s/60s. The later John Hissey, was a railway wagon maker, but the CPR wasn't built until the 1880s...and nothing in the census enumerations suggests a military affiliation.
Exceedingly connorbious*.
ajk
* a word made up by my parents. It means whatever you want, depending on the context.