If you search back through the previous threads you'll find several with "Put Your House In Order" or "Rainbow Quiz" in the title. Unfortunately there's also quite a lot of relevant ones with just "Cryptic" which doesn't help the search.
I think Bushman's clock is right. Because:
"early colonists" of Australia were the Aboriginees (who came from the s.pacific islands). "Settlers" came much later,i.e. the white man. Also "bushman's clock" is a local name for the Kookaburra.
Thank you all for your help. I've been struggling with these charity quizzes for a couple of years and never got a full house, but now know where to come for help. But I'll not cheat and try and answer as many clues as I can using " brain power " and my trusty dictionary. I used to be a member of Mensa but now have lots of " senior moments " Oh well " C'est la vie "