My BIL uses a similar, very similar design to that one, for his salmon smoking. It is based upon 4x8 plywood, and the fire box is a hole in the ground. Super inconvenient when you are lighting the fire, bent over a hole in the ground. But, it works great for cold smoking and warm smoking. Yours is nicer, with that fire brick on the bottom.
Whip It Off, Chambers!
"perhaps...but then again...maybe not..."