Thanks Rob, I appreciate that. Hope you didn't get hit to hard by Helene.
To be clear, (and I'm not picking apart your statement) I really tried not to hog it out. Removing too much is what screwed things up for me previously. It was actually my goal to remove as little as possible beyond what was needed to match the shape of the head port and avoid bell mouthing the opening.
It might look hogged out because of the size of the head ports but it's pretty minimal as far as material that was removed. Very little was taken from the sides. I'd say about 3/16" was ground away from the roof and floor. I suppose 3/16" is a lot relatively speaking but the S.V. has the room. Plus, it wouldn't make sense to stop short and not remove enough to match the shape.