This only supports the information you have already received on Harry and Beatrice Underwood.
In 1954, both Harold and Beatrice are enrolled in the Oxley electorate just east of Brisbane. A major city in this zone is Ipswich, but the Esk area and cemeteries, which have been referred to, are just a few miles north of Ipswich.
I would like to issue a warning on Ethel May Johnson and New South Wales. Ethel May Johnson died 15 times in NSW between 1930 and 1979. The names of husband's are given, but no George and Lucy exists. Only one, with a father named Steven?? looks as though it could be a mistake, or misrecorded entry, but she would have been born in 1897. Information on her son suggests a Queensland link and, after her separation and divorce, there is little to hold her in New South Wales. As well, it would appear that her sister also spent years in Queensland. I acknowledge the distance between Ipswich in the south and Mossman in Northern Queensland, where Gordon Don enlisted. His service records have not yet been digitised, so they are of no more advantage.
Another sidetrack, as I do not maintain membership, but "Somerset Fields" appears to have a date for Ethel May Locke's death in Australia on ANcestry family trees, but this may just be an unknown date, I guess.