Do I take it, then, that the original record shows nothing beyond what Ancestry have transcribed? 
If you did take it that way, you would be missing out on further info. What Ancestry has transcribed is NOT from the original record. They do not claim it to be from the original record. It is from an INDEX of the NSW Registrar General's Office for Births, Deaths, and Marriages, and most likely from the index originally prepared in the 1930s, based on volunteers reading from the Reg Gen's records.
Civil Registration commenced in NSW in 1856. You can tell the difference between an Early Church Record held by NSW BDM and a Civil Registration held by NSW BDM because the Early Church Records (mostly pre 1856, but some as recent as 1890) include the letter "V" as part of their index reference no.
Your chap's birth registration is listed at the FREE to search website that NSW BDM offers. You do not need access to Ancestry to find the NSW BDM index. Here is the link that is listed at RChat's fantastic NSW Resources Board (lots of other live links there too)...
http://www.bdm.nsw.gov.au/bdm_fh.html and
Registration Number is 2445/1856 (1856 being the year, and 2445 being the Cert no allocated by the Reg Gen's office. There will also be another number, the one allocated by the local office where the registration was made ...... Paddington District, a district in the Eastern Suburbs of Sydney).
The mother's surname DAVIES
The baby's first given name and any initials for further given names DAVID E J
The given name of the father of the baby OWEN (where the parents were a married couple)
The given name of the mother of the baby JANE
The district where the registration was made PADDINGTON
To complicate matters further, in the initial stages of civil registration, it was possible for a birth to be registered in NSW where the baby was born OUTSIDE of NSW, was not yet 18 months of age and was living in NSW.
So a 1856 NSW birth registration should give you
Where and when born (address eg 'at sea off the coast of NSW' or street and town in NSW, or if born in rural district the name of the farm/station etc, name of the day of week and the full date,
The family surname
The baby's given names (all, not just initials
) and if present when birth being registered
Father's name, occupation, age, and birthplace
Date and place of marriage and any previous issue (of the marriage)
Mother's name, previous name/s, maiden surname, age, and birthplace
The name of the informant (usually a parent, but could be an older sibling, or relative, or family friend, or householder etc), informant's relationship to the baby and the informant's address
The names of the witnesses (doctor, midwife, nurse)
The local registrar. (until WWI, the info was usually given verbally, so this is the name of the person who recorded the info provided .... verbally, so subject to various accents, spellings, poor handwriting, etc).
Here's a sample of a birth registration held by NSW BDM and displayed at the website. It is for Henry LAWSON, a famous Australian Poet. He was born 1867.
http://www.bdm.nsw.gov.au/resources/b1867-11928.pdfCheers, JM
