That brings up a question: If a lot of coins worth $50 sells on eBay to some know-not for $500, should the post office be required to pay $500 for the loss of the item? Does the seller here really believe that the lots that sell for "5-8 times retail" are worth that or is his business model bases on the ignorance of his patrons? Perhaps he knows that collecting $500 on an insured parcel worth a fraction and gone missing is not worth the fight???
I think it would be fun and educational to see you perform the steps to clean the Axumite coin. Can you take a picture of each step and comment on the results. Of course, we all want to see the "After" cleaning picture. : )