G'day Daz
This what I'm going on. My sincere apologies for getting it back to front !!!
It's really difficult to say if you'll need the brackets or not, but to explain what happened in my situation. I hope it helps in some way...?
As far as I know, AU1 and AU2 uprights are different and there are two different uprights for AU3. Whether you need adapter brackets to fit the Premium brake calipers depends on what uprights you car has.
My AU2 TE50 never had Premium brakes (it was an option on T2 TE50, only standard on TS50 and TL50 in the AU2 T-series range). My car had standard AU2 brake setup.
I purchased the calipers off ebay (brand new) before researching and read nothing but "you need adapter brackets." I tried everywhere to find the brackets and the only lead I had was to have some made, using a borrowed bracket as a pattern. The calipers and discs sat in the box under the bed for months.
One weekend I had the front wheel off (to replace a front wheel bearing). Once the new bearing and hub was on, I decided to "test fit" a 330mm disc to see how it looks and see how far off the caliper fitment was. Once the disc was on, I couldn't see how the Premium caliper wouldn't fit, so tried it. Everything lined up, no brackets, no stuffing around.
They are however fitted on the leading edge of the disc (as opposed to the factory fit being on the trailing edge of the disc).
I can't give you a definite idea of whether you need brackets or not - you may... HOWEVER the only way I knew I didn't need the brackets was to just bolt it all up and see.
Glad I didn't just go on what I read otherwise I'd have spent a good few hundred dollars on brackets I didn't need.
Don't want to give you false hope but my AU is a late AU2 also (May 2001).
Many thanks to 'macman' for his support.
Cheers