Bailey,
we often refer to them as "Postmarks" (The black markings)
The little green stamps. often called "bantams"
2 lines ?
possibly a manuscript cancellation part of a "slogan" postmark.
(possibly, but it may be a 3 digit numeral) "14" is a barred duplex postmark, SWAN HILL re allocated to Melbourne.
The "R" is an auxilliary marking, indicating the letter / parcel was Registered.
The Barred VICTORIA comes in 2 parts the barred section is called the "killer", on the left hand side would be the Circular Date cancel indicating the location.
Opinion:All marks shown are common.
This should give you an idea on "Duplex" postmarks (Barred numeral and CDS Circular Date Stamp)
