Stone Oven

I've been ignoring the old stone oven in the back yard for years. On more than one occasion I tried to use it as a grill, but it was a failure, or rather I was the failure. After looking at some articles, I realize now that this is probably meant to be used as a slow-cooker oven instead of a grill. So I've cleared off the vines (almost) and am ready to give it a shot

First, it is pretty big, about 6 feet. It has an oven door in the front.

The grate sits about 10 inches down from the top.

And under the grate (behind the door) it has a big space, probably about 2 feet from the floor to the grate, almost 2 feet wide and 2 feet deep.

And a stone shelf extends to the right, at the same level as the grate, and it's about 8 inches high.

So how should this be used? My guess would be to put the food in the shelf to the right, put the charcoal into the box (a bunch of it), put some wet wood on the coals and then completely close off the opening above the grate so that the smoke is pulled up the chimney. This would keep the food away from direct heat. I guess I should use a thermometer to be sure.

Sound like a good plan?