I don't think all these chicks are australorps and maybe none are. There's a good chance they are mixes - especially, if all the chickens on that farm were running loose together.
Australorps are black and typically have yellow or white tummies and faces when newly hatched. Australorps also get white wing tips that later go away, but other black breeds, such as Black Andalusians or Black Jersey Giants are colored the same. The red lacing is not an Australorp trait - I can't think of any black chicken that would get red lacing. Gold Laced Wyandottes are very striped as babies - they don't look like the chicks in your pics.
Here's some black chick pics:
These are australorp babies:
Barred Plymouth Rock:
Black Ameraucana and Easter Eggers (fluffy faces - yours are not this type):
Black Cochin bantam (feathered feet):
Black Copper Marans:
2 Black and 1 Blue Andalusian:
Edited to add: There is nothing wrong with mixes, if that's what yours are - just means you'll have to wait till they grow up to see what they'll look -- Surprise chickens! They'll still be entertaining and lay nice fresh eggs.