Thanks to “Penrith City Star“.
The inside text reads: Penrith Public School’s library stands on the site of a portable library building, and before that a previous portable building. In 2010, workmen excavating the foundations found these “school milk” bottles buried deep in the rubble. One is embossed “1/3 PINT PASTEURISED MILK”.
See the original blog entry of our archeological find HERE.