I need to rebuild the carbs on my '73 Merc 115 inline 6 motor. I don't know which carbs I have and don't know how to identify them. One kit is for a KD-6A, 6B, and the other is for WMK-3, 10, 15, 18, 26, 28, and WMK-5, 18, 26, 28, 32, 36, 40, 41, 41-1A, 41-1B, 41-3A. How do I determine...