Correction very well described.Do I see it correctly, that you dismantled the first back-platform, which was rectangle and produced a new one, which has a trapezoid form, following to the hull lines?
I know this old discussion, if Jean Boudriot made here a mistake in his monographie
Take a look at the plan and my red "correction"
View attachment 75549
A Look Inside in the planset you can find here: