Is this him in about 1884ish? (Sands directories had closing date of October the year prior to allow for time to publish, so an entry was lodged by Oct 1884 for the 1885 Directory)
Sands 1885 Sydney Alphabetical Directory
Thomas VINCENT, market gardener, Rickety Street, BOTANY.
I'll have to ask the family if there's any rumours of being a gardener. Reading the link that Sue found, it makes a reference to him in 1858 when Jacob Bondor leased the land. Thomas Vincent claims 20 year possession of the land so that would be too far back.