I have answered two emails from Fred. I told him that I consider it to be a defective chip that got past quality control. Yes, it is an error because they did not plan to produce double-strikes. Do I consider it rare or valuable? No. Will it be listed in TCR-11? No. I advised him to keep it if he likes it. I also wrote that an error collector may want to purchase it. If it were mine, I would have returned it to the seller to get one that was not defective.