It wouldn't have a one-piece windshield from the factory, it would be two-piece. Chances are that one side broke and the owner at the time found a one piece glass. Also, John Parker remanufactured the gasket, but only for a one-piece. The divider strip was not reproduced and so the old one would have to be connected somehow to keep the car as original. Chances are, the old divider rubber was in lousy shape - switching to a one-piece was less labor intensive.
