Looks like what I've been fixing. There's core there on either side of the end of the keel. Knowing what I know, I'd be tempted to try from the outside first, unless you have some other compelling reason to remove the floor.
Not much thickness to the skin on the outside there, probably why we have cracks. Really thick on the inside. Bet I've got 80 hours into the job so far. Getting close to done but it ain't over yet.
