www.elitefourum.com/t/base-set-2000-a-guide-to-the-last-print-of-base-set/22312/1
www.elitefourum.com/t/guide-to-understanding-fossil-zapdos-15-62-variants/30830/1
You’ll have to do some reading and link clicking on the fossil thread link, im not sure if there is a guide on the Australian Fossil or not on here. Enjoy the learning dude!