The National Archives of Ireland has a poignant letter from a criminal transportee in Australia as its Archive of the Month. The man, David Gordon, writes in 1825 to his wife, Mary, left behind in Ireland with children, urging her to join him. He describes a place of opportunity available to them in New South Wales and asks her to request permission for free passage for the family.
The document, and subsequent communications with the authorities, are from the Chief Secretary's Office Registered Papers collection (CSORP).
CSORP's website is worth investigating. It's a product of the Crowley project which set out to catalogue the registered papers of the Office of Chief Secretary of Ireland from 1818 to 1852. So far, the first five years of papers have been listed and catalogue entries for 1818, 1819, 1820, 1821 and 1822 can be searched on the dedicated website. These items are available for consultation at the reading room of the National Archives of Ireland.
Cataloguing of the years 1823 and 1824 has begun. However, last time I enquired I was told work was not in progress due to staff departures.