I do remember ours had a damper we could close if the oven got too hot. As for the air vents, if I remember rightly, keep the one above the firebox closed as you are heating things up. When you have good coals and are ready to cook, that is the time to open the one above and damper down the one on the bottom.
When starting keep the top intake closed. This allows air to rush in and up stack without giving the fire oxygen. The indoor air cools the flue killing draft. I can't see the lower intake, is it below a grate and the upper one above the grate? (Primary and secondary for coal) Some will have other inlets into exhaust you need to make sure are closed. Like a barometric damper, they allow indoor air to slip up the stack to slow draft to prolong a coal fire overnight. What diameter is the chimney flue? It takes a flue the size of the stove outlet to produce enough flow around oven. Never circulate around oven until chimney is up to operating temp. My stack temp (pipe surface) is currently 250 which is approx. 500 internal, oven 300 without turning it on, stove top lid over firebox 510, stove top surface around lid 480. 68* in the farthest bedroom away, 0*f. outside. Going down to -6, it will creep up inside overnight to 72, then drop back to 66 by morning.
I appreciate the information. I’ll burn it today using your advice, and see what temperatures I get. It’s all 6” pipe - starts out oval at the base. I do get plenty of draft. I baked some biscuits and found out quick that it’s easy to burn the ones closest to the firebox. It sounds like you heat your house well with yours- mine would never keep a fire going long enough. Thanks