Gluing up blanks

I have 2 pieces of a broken 10’ Yater that I want to make a funshape out of. My question is this: In the original blank the there were 2 stringers that started together from the nose and ended up about 2 inches apart in width at the tail. So it formed more or less a really long narrow triangle. (I have seen a lot of the recent Yater’s with this stringer). What I want to do is saw the blank in half, glue in a new stringer and reshape something like a 6’6" fun fish. Any body have any thoughts about putting in a new stringer? If I don’t the old board’s stringer will not line up. (I have to cut at lesat 6 inches off of both pieces to get a striaght perpendicular line to refit). ANy help is greatly appreciated. Drew