I have posted an audio clip up there ↑ in this very thread!
All those examples are the same sounds to me. With how English spelling is, there are 'au' words I say differently (I say "because" like "b'cuzz"), but I can't think of any that would rhyme with cross
I've also heard giraffe pronounced "girarffe" by a Brit. (Or at least implied since it was rhymed with "scarf" in a Julie Donaldson book.) Maybe there's some rule regarding "R" sounds on the ends of certain vowel sounds.
Aha! You have discovered the non-rhotic accent. Most, but not all Brits (along with Aussies and some rural Americans) do not usually sound out r's unless they're followed by a vowel. In my northern England accent, giraffe and scarf have different a sounds, but also scarf has no audible r. I'd guess Julia Donaldson speaks more Southern or RP so giraffe would rhyme with scarf would rhyme with half.
My buddy (we're from Canada) went to Australia for some time. He was a smoker, and lived with a bunch of other smokers. In Canada, if you want to ask someone for a smoke, you say "Can I bum a smoke?". In Australia, it's "Can I get a fag?" In the spirit of international cooperation, the expression soon became: "Can I bum a fag?" Much maturity.
I thought about this a little and I agree that I don't think there's any English words other than "because" that have the ɒ sound for "au". They're basically all ɔː.
You can look up the pronunciations for those symbols by searching for "IPA English". It helps for describing vocal sounds.