I don't have the kit, but it sounds like Academy must have made an error.
The door is in indeed in the "front" (i.e., the side facing the ship's centerline). The roof of the head is supposed to be curved downward on the "back," so it meets the ship's rail. There isn't supposed to be any space between the roof and the rail.
Sounds like Academy may have made the roofs flat on top. That's wrong; the curvature is clearly shown on the George Campbell plans, as well as on numerous photos of the ship - and the big Revell kit. (I don't know about any of the others.)
Shouldn't be too hard to fix, with some styrene sheet or something similar.
Hope that helps. Good luck.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.