You are right, it this incorrect on the PDF. The HP was perfectly round. The best plans I have of the across sections is of the VIID (10 across sections for the VIID & 8 across sections for the VIIC) and the PH is round in every one of them.
Thanks for the vote of confidence, guys.
I spent a fair amount of time making my scaled-down forms exactly from the plans in Anatomy of the U-boat book, using round sections as those plans indicated. But when I tried to put my PH inside the hull kit, it would not fit inside as the sides of the sections were too wide and it pressed the hull open so the top deck would not fit. As such I was forced to make some alterations to allow my PH to fit inside the thick plastic hull.
I know my PH is not exactly accurate as per published U-boat plans, but rather it is a close approximation that fits within the confines of the thick plastic kit hull. That meant making alterations from published plans. The plans do not take into account we are trying to adapt things to a plastic model kit; you have to take into account the thickness of the plastic material the hull is made of... and that Revell never made efforts to make internal dimensions accurate.
I had hoped my efforts would be appreciated as a way to make up a mock PH that people could use as a foundation for more detailing.
It was never my intent to make the PH a perfect replica, but rather it was my intent to make a general shape that would FIT.