I recently contacted the Librarian at the State Library NSW and they were able to view the original Cathedral records for Jacobs marriage. The spelling of his parents names transcribed onto the record of marriage by the NSW BDM register were similar but incorrect.
The library advise the marriage is contained in Reel 0014 of the Parish Records for St Mary's Cathedral however they are restricted and cannot be copied. The writing on the microfilm record was very clear and easy to read:
Name : Jacob BROWN, Status : Bachelor, Birthplace : Austria, Rank or Profession : Mariner, Age : 24, Usual Place of Residence : Sydney, Parents Names : Domanic BROWN, Jonenne LUCCIDGE, Father's Trade : Farmer.
Can anyone give me a lead on where the family may have originated based on the new spellings?