We just added this to our inventory this week. I thought it was a neat piece and I wanted to share.
Yep that's a die adjustment piece. (Many pieces advertised as die adjustment coins are actually major grease filled die coins.)
Yes, they affect both sides of the coin. Arnold Margolis used to say (when referring to die adjustment strikes & cuds) that you cannot clap with only one hand.
Of course, the term "die adjustment strike" is untenable as it is impossible to determine whether the weakness is due to the coin being an escapee from a test run or simply the product of spontaneous equipment malfunction.
