This was in my PO Box when I went there this morning:
This one was one that I did not realise I didn't have as it was not on my list of fdi postmarks. Thank you very much for finding this one for me.
Phoenix tells us that the Engadine Post Office opened as an RO 15/11/1922 & became a PO on 1/7/1927.
Engadine is a suburb in southern Sydney, NSW. Engadine is located 33 kilometres south of the Sydney central business district, in the local government area of the Sutherland Shire. It has a population of 17,375 (2016 census).