Hi Brendan
My gr grandmother was your gr grandmother's older sister Annie Elizabeth Caless. I've got copies of birth, marriage and death certificates for Heber Caless and Annie Merritt and some info about their parents. If you are interested I could send you scanned copies. I visited Charters Towers last year and have details of the burial plot for Heber Caless(no headstone)and a few others (including my gr grandmother) that might be of interest to you. I wasn't aware of your Harriet Emma's connection out there or I would have looked for her also. Annie Caless (nee Merritt) is buried in Ayr. Happy for you to email me directly on helglenn@internode.on.net if you would like certificate copies
Cheers
Helen