How Did Something Like This Circulate

That's a good question.

Maybe a non-collector kept it and carried it around to show people. I can't imagine it passing through that many hands without someone pulling it.

Being a full sized dollar, it is NCLT.

Because it is NCLT, I think such an item would never have been released in the normal way that these NCLT items would have been released, and therefore such an error would have been easily spotted. I would say for that reason, it should be quite rare, unless that staffer had a small sideline 'business' going.

I can only guess, but my guess is that the error has been retained by a Mint Staffer, and given to a friend personally. It has subsequently found it's way to ebay.

I have a half thickness English Penny of 1965 that has probably never circulated. It was struck in the last months of production at Tower Hill in London, just before The Royal Mint moved to Wales. Apparently some of the staff were upset about having to move out of London to Wales to keep their job.

Some of them deliberately had mint errors produced, and just threw them over the perimeter wall out into the street for the Public to pick up. I think my half weight Penny is one of those.

That is a very interesting Ike,