Mine is very air tight. The 116 and #6 Baseheater are pretty close from the base up except that the #6's have a split feed door with a latching handle. Our 116's have the same size opening but a single hung door. Mine fits nice and flush with no movement when closed. The loading door isn't nearly as importent (although it should fit right) as the ashpit door. When I say tight, I mean when you lower it down into it's notch. Our loading door normally has some play in the hinges so we can lift up to open and close it. What William meant there, is that it sits flat and flush when closed against the stove body and there is no play or movement when closed. In all honesty though, it's the ashpit door and the primary dampers that really makes the big differance in controllability.
Most all of your fire control comes from below. Mine fits nice and tight. I can close a dollar bill into any portion of the ash pit door and it's stuck in there and might tear unless I loosen the door. Even my loading door will hold the bill though, but that one, I can pull it out with a little resistence.
The two primary dampers should also be nice and tight to the door. The springs should feel like they are applying resistence to opening and closing those vents. Obviously I just went totally through mine and sealed every single joint too, but as William said, if your ashpit door has any play or does not sit flush, it is adjustable by the pins but be careful of those hinges. You would notice though if it wasn't a good tight fit as you wouldn't be able to dial the stove down when you wanted. I see now that you said you haven't had it hooked up yet.
Just make sure your loading door sits flush when closed and doesn't "rock" at all, and the ashpit door and vent springs should all be good and tight (Try the dollar bill test).
Thanks about the brickwork. I can't take credit for that except for the moving the location of the thimble. That was all here when I got the place with a woodstove on it. I call it the stage because I used to have my bass and amp on there. I think it's cool too but Kim calls it "that monstrosity of bricks"