The other interesting thing is there's a Sydney Warren Bachelder b 1887 in South Africa. Father Arthur, a compositor, mother Catherine nee Blomstein
Frederick and Elizabeth Naomi are baptised as adults, after their father's death. I wonder if Arthur and Sophia weren't married and they, and Edward, are actually registered under another surname? Might explain Frederick being given a birth cert for the nearest name to Bachelder, what he thinks would be his birth surname