I have had this carb adapter floating around in my junk box for close to 40 years. It's time to clean things up and if this has a purpose then it won't go to the aluminum recycling box. It may not even be for an automobile. It's 1-3/4" tall and has the letters "D.P.-F" cast in the side. Can you identify it? Paul
Dodge/Plymouth - Ford??? there were two bolt patterns for Carter 1 BBL carbs, pre 40 and post 40. My guess is the undrilled flange gave you the option of position as well as bolt pattern and allowed a Ford (Stromberg 94/97) to be mounted on either size of the Dodge/Plymouth manifold.
Plym 46, there's just no foolin' you. You are exactly right. That was an adapter made for coverting a 1 barrel to a stromberg or 94 and the capability of turning it as you have said, in either direction.