In brief: Sold a 2024 IWC Mark XX on eBay. Watch went to Stoll & Co authentication center. They could NOT open the case back if the watch and therefore cancelled the sale. They then sent the watch to the WRONG address. It took countless hours of work to recover the watch. Eventually after two weeks I received the watch back only after they CHARGED ME for shipping it back to me. Not only did I lose the sale but I lost the shipping cost to the authentication center and then had to pay for it to be shipped back to me. Horrible experience. Use accountable sites like watchfinder instead.