OK so when all else fails, ask seabreeze.
We have a comprehensive WA bird book, but can't find this fellow in it.

we think it's a "honey eater" the "singing honey eater looks somewhat similar. but not close enough to be it.
I've been trying to photograph it for ages, but it normally disappears when I get the camera out. Today it stayed nice and close, and I got several good shots.
Concur, Singing Honeyeater. Always welcome my daughter in west swan has one that comes in and cleans up all the moths and mossies from around her carport light each morning.
A useful site for bird ID is www.birdsinbackyards.net/finder
Maybe they have a forum that's open for enrollment