This forum works best when we can tell you how to rebuild the boat in a way that is stronger or as strong as it was when it was new, using material that will make it last a lot longer than the first build did. We will do all of that using the methods we know will work. What we cant do is answer a lot of speculative questions that lead to more questions on how to fix something that would not be an issue if we had started from scratch with "our" plan
If you are going to re-build the way it was originally built, then that is a decent plan. It might not be how I would have originally done it, but it worked. Replace original locations and thicknesses, you can make stiffeners taller if you want, no harm. If you want to rebuild using our preferred method of a box system of stringers/frames then we can help on that too. Once you decide on how you want to go, lets delete all the other threads and start fresh.
