Rob Heyen: Thanks for the email, I will try and post some pictures for you.
The first is the trap door in my 24 coupe, that you kick open or shut with your shoe toe. The heater does work and throws a lot of warm air especially for the passenger. The door is in the top floor board.
This next picture shows ( I hope ) the trap door in my center door. Note the trip around the door that fastens in the carpet. After 30 years the carpet has warped so the trim is crooked. The trim and the door were NOS in a box when I got it.
This shot should show a rather rare manifold heater in that the back of the manifold is hollow like a model A. The air is gathered by the cover and directed to the hollow place in the manifold.
This picture should show how the manifold releases the air directly into the trap door.
This is the side of a manifold heater that is not hollow.
This is the top of the manifold, note the two screws that hold the cover on the manifold when in use.
The is an original manifold heater cover and I believe is still being manufactured. At least it looks to be the same.
Next is an original short cover for the manifold with the hollow area.
A snow storm in Wyoming.
\image[riverside snow storm}