You are looking for and reading things in that aren't there silversearcher. The Perth Mint does not get coins struck by outside mints. I doubt the Australian government would even allow Australian legal tender precious metal coins to be struck by another mint even if we asked.
We don't buy precious metal blanks from outside (base metal eg bronze blanks yes). All our gold and silver comes from our refinery sourced directly from mines and scrap from Asian region, and for silver in the past when demand goes crazy (like 2008) we will ship in LBMA bars to top up our refinery output from mine supply (most of our silver is as by product of gold refining, with small amount of primary silver from miners).