James,
I concur with the other posters and would immediately issue the refund.
PayPal offers a guarantee no matter what, so the buyer is going to get his money back anyway.
I would consider re-listing the Comiskey item AFTER Christmas, as eBay activity is already slowing down before the holidays. Add a photo of the back of the envelope next time so that everything is transparent. I've always found the time after Christmas a good one in order to get good action on auctions. People are at home and on the computer. Maybe people are buying the present that they really wanted for Christmas.
