Welcome Lunithy
I'm a fellow Aussie Amiga user with a few machines, some A2000's
I also bought my A500 in Nov 1986 Rev3 mobo with KS1.2rom and the C= key instead of the left Amiga Key
The store I bought it from wanted Ca$h upfront and said the A500 was a special Order placed with Commodore Australia, I had to wait weeks for it to arrive. Sales guy said it was one of the first A500 systems pre-ordered into Australia.
Wiki might state '87 official A500 release but I'm sure I got mine in Nov'86, I'm still seeking the receipt I got with it.
Az