Mystery intake manifold

[wrndln]

Yesterday I got an intake/exhaust manifold at a swap meet. The exhaust manifold part looks like a later model A manifold. However, the intake manifold is one I have never seen. It has a flat top and a couple bolt bosses on the firewall end. It might be a right hand drive unit and maybe a later manifold, i.e. Model B manifold. I took a couple picture of it and posted them below. It would be great if anyone would post what it is - year and usage.
Thanks
Rusty Nelson