Do you know anyone born in South Australia around 1958-1960?
Their own birth registration should be close in terms of numbering to the Bomford book and page registrations.
For example, if someone born in 1958 was registered in, say, Book 44A, that would support the numbering system in the Bomford certificate.
Or any book at all. I haven’t seen any reference to any books at all (so far) in Australia.