I have conducted a search on our collection database and found that we have a migrant selection document for David Stevenson, the details of the item are in the table below.
I recommend that you submit a reference inquiry using the online form at http://naa.gov.au/collection/forms/imm-inquiry.aspx, to get a copy quote for this item, and to see if there may be other records in the collection such as a naturalisation file (if David ever applied for Australian citizenship). Our reference officers will look into what records are available.
Unfortunately, our records may not be able to assist you with your search for his/his family's current whereabouts as they will relate to the period he came to Australia. The records of the National Archives are publicly available when the reach the open access period as defined by the Archives Act 1983 (we are currently releasing information that was created in 1981 or earlier).
As you know the area in which he settled, you may be able to find his current whereabouts on the electoral roll, however, these are not electronically available for searching - you have to go to an Australian Electoral Commission office. You may need to find a research agent to help you search - maybe a genealogical society may be able to help you with finding someone to investigate the electoral roll on your behalf for a fee. They may also have some ideas of where else you may be able to search, Our local society in Canberra is Heraldry & Genealogy Society of Canberra and their homepage is http://www.hagsoc.org.au/
Alternatively, the Salvation Army or Red Cross may be able to make enquiries for you: