2001 Silver Coloured Kangaroo Dollar - Copper-Toned Spotting

I've decided to sell some coins that aren't in the focus of my collection. That said, I'm selling my Colorized 2001 Silver Kangaroo Dollar. I've had it for a while but the frustrating thing about this early series of Kangaroo Colored coins is the spot toning on (some of) them. I've read that this was caused by tongs or clamps that were used in the painting process. The spot toning is copper in color. I've rubbed a spot on the rim a little and it's silver beneath toning. These coins were, evidently, the first legal tender coins that the Royal Australian Mint allowed to be painted or 'altered' before sale. I believe Downies had something to do with this limited edition as well?

Has anybody had experience with this spotting/ toning issue on the earlier series Kangaroos?

Thanks for your help!