Just received an answer from a gentleman on a different forum. The carburetor was sold as a package including the intake manifold, which explains why it is an updraft rather than a side draft.
Thanks to those who have looked at this post.
Jon
Just received a picture of a Stewart (Division of Detroit Lubricator) carburetor stamped "Model FORD".
Last patent date is November 1911.
Carburetor is an updraft (not the normal sidedraft used on the Ford model T, and has a cross flange.
Very difficult to be certain about size from a...