[GradySailfish]

Ok...I see whats going on. You can glass those cracks from the outside...simply grind away and then add a 3 layers of 1808/1708 over the area that is cracked. I didn't have those cracks in the stringers, but I did do some damage to them as I removed the deck, and thats how I fixed them.

I'm also willing to bet, the foam in those stringers is waterlogged and warrents removal and re-foaming. Check that out and make sure. Otherwise it looksl iike your project is looking good.