Gray-Dort Motors Ltd was a Canadian automobile manufacturer based in Chatham, Ontario. The company built cars based on the American Dort, and its fortunes were closely tied to those of its American counterpart, ceasing production when the U.S. firm closed down. Gray-Dort was among the most successful Canadian-built cars of its era, at times outselling the considerably cheaper Chevrolet. The company's origins traced back to William Gray & Sons Co.…