Dilferules
Well-known member
COMC probably can't/won't help, but you could try them if you have not already tried. If it wasn't an auction, good chance the buyer snagged it on COMC, not through ebay (as you save $ going to their site direct).
If the actual individual who sold it through COMC was known, they could be contacted and might have a buyer username if the buyer bought it on COMC. But based on the pics in the OP it was probably actually sold on eBay, otherwise I would think COMC would just remove the eBay listing immediately if it sold on COMC, and it wouldn't say "sold" on eBay but rather just the listing was ended.
Even if it did sell on COMC and the seller's ID was known, there's no sure way they'd know the buyer ID since if the buyer wasn't a COMC member they could just buy it in their shopping cart. I don't have much listed on COMC and rarely make sales, but this is what the "sales history" looks like:
I can see usernames for COMC members that bought the most recent couple of cards. But on the third one a non-member went to COMC, put a few items in their cart, and checked out...and I get no info for them. Then on the 4th one, eBay sale so I get nothing.