But there was a small breakthrough; a 1983 death notice for Marthinus Swiegers, looking very much like great aunt Connie’s husband. His pre-deceased spouse (1977) was Constance Louisa, no maiden name unfortunately, and daughter Johanna Louisa. All in all a pretty good fit.
So, of course, I spent some time looking for more on Ralph and Edith and anything on Doris but, alas, again to no avail. Very frustrating when you make a minor breakthrough, get all enthusiastic again but find all the old dead-ends are still there.