The star in the centre of the grille makes this a 1958 model.
Ford Australia did not import US 1957-58 models, they used a mixture of US and Canadian parts to change the look of the US 55-56 models. 57 models used a modified 56 grille, and 58s used a 55 grille with the star in the centre and side trims from some other model. These were unique to Australia.
1959 we got the US 1959 model, then again for 60-61 we had unique models using US/Canandian parts, then got the US 1962-4 mid size models.