Here is some photos of various one, two and three wire porcelain cleats that I have. Just like nail knobs and spools, the companies that made them were endless and it's fun to collect all the different markings and shapes. You can see details of cleats on Elton Gish's excellent website but these are just pictures of the many markings. Left to right A P Co., Brunt, Circle C, C.O.P., Diamond, Duggan, E.P.Co.,E.E.P Co.,FEDCO, F, and Findlay.