Please Help ID a 31 exhaust heater, odd shape

[F&J]

Hi, I bought my first Model A "keeper" this summer. (barn-rust condition, but perfect mechanical driving/stopping). It is a Martin Parry huckster 1931, sold new up near the Vermont border in western/central Mass. (cold climate)

The manifold heater is an odd shape that no one around my area has seen before. It sweeps down to the pipe attachment area, and it's shapes & mass seems to be getting the most heat possible? The problem is no casted name and worse yet, the tin cover is long gone. I will make a cover at some point, but would like to know what kind it is, or if you have seen one to get a look/fabrication idea of the cover I need to make. Thanks, Frank