From 1854 until 1901 the states maintained their own military forces. Consequently personnel records may be held at the State Records Office in the state of enlistment, or from the National Archives Australia:

National Archives Australia
GPO Box 4325PP
MELBOURNE VIC 3001

 Ex-SERVICE ORGANISATION (incl RSL) MEMBERSHIP

Central Army Records Office is able to confirm ARMY service for ESO membership. The ESO should contact caro.hq@defence.gov.au in the first instance. If the ESO requires additional information they will need to supply the written consent of the ex-member.