I believe the odd ball ones really weren't intended to be minted. It's just one of those things, perhaps at the place where the brass rims are manufactured, where a few pieces were found on the floor, on top of a table, etc. and then just thrown into a batch of the regular ones that were on the way to IGT. The workers didn't care, in fact, no one even knew about them at the time.

But minted they were, and every bit of an error, as the SAF's "die clash" strikes are, in fact, more so. It's too bad the "powers to be" don't recognize them as such.

My Silverton was chemically tested and is absolutely a coppen rim, so I don't care what others say about it's authenticity.

Be careful of that Venetian, though... too many coppers are just tarnished ones, and many of the experts get fooled by them.