According to PlantNet, E. saligna occurs north from Port Jackson. The intergrade varies greatly, including the fruit. Inland, smooth-barked trees on the south coast are clearly the intergrade and not E. botryoides.
Have a look at https://budawangcoast.naturemapr.org/Sightings/4343793. Your fruits look like E. botryoides, but the bark looks like E. saligna as you know. From Sydney to the border and beyond seems a big distance for such an intergrade.
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