Odd aftermarket heater in 340

I did some work on a 340 yesterday and noticed that the heater is different from what I’ve ever seen.

The case is a lot flatter than the original, but seems to have been made for saloons of this era.
It doesn’t move any more air than the original (perhaps the red connector is for a secondary fan which isn’t currently working).

Anyone ever seen one of these? Who made them?

Looks like something Kenny might have plumbed up. Paul