Chuck sorry to say your probably not going to get any where with eBay unless you say it was stolen property and filed a claim...
I would make another plea to the seller...empathize the fact it is a one of a kind, very personal to you with your photo in it...perhaps tell the seller if they will not give you the contact information of the buyer at least forward your story to the buyer with your contact info...
The seller has the buyer's contact info I really think that is your only hope...
Good luck...