Brad Allen is probably your guy to answer this. He has a ton of pictures of heaters
HERE.If he doesn't show up here soon, send him a Private Message and point him at your thread.
[on edit]
Here's another of Brad's photos showing a fresh air heater installed. Looks like the control cable is in the hole punched in the dash toward the right side, and the valve control just below that and clamped on the bottom of the dash.