Ottwell Health heater questions

[Binger]

I bought a '31 sedan that came out of a barn and inside the car I found this piece in the pictures below. It has the words 'INTAKE STOVE OTTWELL DETROIT' on it. I am assuming that it has to do with the door in the firewall. Am I placing this part right in the pictures? I have never seen one of these before and it fills up that little air gap between the manifold and the fire wall. let me know if this is exactly how this piece is supposed to be used.