Working on a 1957, Wizard Super 10, Model WH-7A. I need a Needle & Seat for the carburetor, AJ45B. Trying to figure out the part number for the Needle and Seat. The Mercury KH7, Mark 15, Mark 20 and Mark 25 all use part # 1399-1138. Though the Merc manuals do not state the carb model numbers. Please help.