Sum R Air manifold heater

[myjunk]

I assume this is not for a Model A, but it came in a box of parts I recently acquired. Anybody have any information about this, or know what kind of car it may have fit? Thank you

 

[glenn in camino]

The part that looks like a heat register goes under the floor in the back seat. It's plumbed into the top of the manifold to distribute heat into the back seat passengers.