Rob Garratano sent me these photos. He is trying to find out what year this carburetor was released for production. I don't know but suspect it is late teens or early 1920s. I hope others can provide some feed back.
I too have a Zenith Carb from a single cylinder 3hp two stroke engine from the late teens, early 1920's, and it is clearly named as Zenith on the float chamber cover, but very different to Dick Days. Does anyone have any information on what should go in the two air intakes etc