A Cartier watch found in a bag of donations at a charity shop has sold for almost 10,000, with the funds going to the British Heart Foundation.Finally selling for 9,766 after 46 bids, the Tank Francaise yellow gold model broke records as the charity's biggest online auction sale.The 18-carat gold watch, found at a branch in Hounslow, west London, was verified as a real Cartier product at the BHF's eBay warehouse in Leeds, and was then double checked by experts at an independent auction house.