yeah, it's kinda hard to explain without a photo, but yes.Do you mean that the width of the rectangle tapers down as the chunk goes into the hole?
I bought my chunk in preparation for my build and it's an even square on all sides. What I see in the shots from page 69, it's not even going into the pommel. If the square is 1/4 inch on all sides, it looks as if the top to the pommel is 1/8.