You posted this thread while I was working on my reply in the other Vic numeral thread.

It's a NSW cancellation, type 5. I believe the last numeral design used in NSW, although I'm no expert on that State.
Probably used post 1910 - watermark of the stamp would help confirm that. I can see that the stamp is Die III. Watermark could be V over Crown (V4), Crown over A, or V over Crown (V5.)
You'll need SG to distinguish V4 from V5, and it ain't easy sometimes. Look for the narrowness of the base of crown, that's the easiest way.
Balf