Christie Brinkley once again stunned fans by proudly showing off her endless legs in a dress once worn by the Duchess of Cambridge.MORE: Christie Brinkley shares sensational swimsuit photo for heartfelt reasonThe American model took to Instagram on Sunday to promote Bellissima Prosecco, the vegan and organic spirit backed by her, and looked stunning in a navy polka dot Alessandra Rich midi dress with button detailing and a white-collar, which retailed at the time at £1,750.In the fun photo, the