From what I've seen it looks like the hulls are built of 2 sides, seamed top and bottom, no top cap.
Bill, sleeving the daggerbd trunk should work well. I do understand wanting to minimize cutting up good panels. But the bottom seems pretty broken up, needing a fair amount of reinforcement, which I'd prefer to do inside as much as possible. I'm pretty comfortable that I can do a strong job opening up the hull somewhere, I just want to do it in the least stressed area.
I do appreciate your and other's encouragement that it is indeed fixable.

Dave