Operational Control
There was never any Operational Control at Bankstown nor any of the other Secondary Airports as they were called. Operations Control was located at the capital city primary airport (SY, ML, AD etc.) where the Senior Operations Controller was located. The Briefing Office at the secondary airports was typically staffed by an FSO and an ATC briefing officer. The ATC would most likely have endorsements for the BO and the tower and work both on a rotating roster.
Both BO staff members could accept plans, however, only the ATC could accept IFR plans and give them Operational Approval. Although the ATC member approved the IFR plan, when the plan arrived in the Operational Control Centre, it was again checked and a paper strip was filled in and displayed for the Senior Operations Controller to monitor for the duration of the flight or leaving the FIR.
I did ATC PF TWR and BO for many years. It was surprising how many plan errors we picked up but it was a great place to meet the pilots.