While waiting for Chucky to get back with certificates,(possibly a little while with Sydney now closed down), I have been looking at possible Robert Vaughans ....
His marriage to Mary Winnett was Roman Catholic, even though the Winnett family were protestant.
His son was a printer so likely he came from a background with education.
There might be some link to Muswellbrook district where the Winnett family were.
This one fellow below interested me, - the marriage record for Robert Vaughan to Mary I Winnett might shed some light.
Robert Vaughan (CONVICT) per Dunvegan Castle (2)
Arrived NSW 16 Oct 1832 (bonded on arrival)
Prisoner 32/2608
Native of Dublin
19 years old
Roman Catholic
Can read and Write
Profession Attorney Clerk
Crime stealing books
Tried Dublin city 12 April 1832
Sentence 7 years
Former conviction 6 weeks
Complexion Ruddy & a little freckled, hair brown, eyes hazel;
Robert Vaughan (per Dun Castle) - Pheonix Hulk Discharge book
5 Nov 1832 good behaviour
Robert Vaughan (per Dun Castle) Newcastle Gaol Entrance Book
Committed At Muswellbrook 28 Dec 1840
Crime Supposed illegally at large
Discharged 7 Jan 1841
Certificate of Freedom no 41/134, date 30th Jan 1841
Robert Vaughan per Dunvegan Castle 1832
Native Place Dublin
Trade Attorney Clerk
Place & date of Trial Dublin city, 12 April 1832
Year of birth 1813
Complexion Ruddy, Hair Brown, Eyes Hazel