I have been trying to find a replacement switch for my 1961 Mercury 800 full gear shift model. It is a 3 position switch with four posts that fits in the end of the single handle control unit. The original switch was wired as follows: Post B went to battery, Post C went to starter solonoid, Post I went to ingition, and post A went to the alternator. It has a separate switch for the choke which wires to the ignition post. There are a lot of three post switches out there but I have not found one that has the fourth post that wires to the output of the rectifier. Anyone have a place to get such an old critter?