Hoffwego, thanks for posting the info. Indeed the heatsink is missing from the card you sold. You've confirmed that it seems to be from manufacturing (UA has admitted that some have been mismanufactured). Nevertheless, the card should have a heatsink to function reliably long-term and you, as the seller, or the buyer should definitely contact Universal Audio so that they (UA) can make it right.
Unfortunately, eBay has become a tool to victimize many and, as such, sellers with moderate amounts of feedback are under a more scrutinizing eye when buyers are contemplating a transaction of any sizable amount from the said sellers.
Keep in mind also that we of this forum, collectively, own thousands of UAD-1 cards and in thousands of cards there is scarcely any mention of a card being heatsinkless.
I don't doubt your claim at all, in fact I posted evidence substantiating it. On the other hand, we DO have a right to question something when something doesn't seem right.
Regards,
Matt