Have you searched assisted immigrants list at the NSW State Records website for your Glew's. And have you already looked at the index for BDMs for NSW. They have just extended the death indexes to 1974 (i think) so you can search for Frederick Glew's death, and therefore get some information on his certificate re birth, marriage,arrival, and children.
Lithgow also has a good family history society. Worth getting in touch with them, if you haven't already.