You're description of how she's built isn't detailed enough, but it sounds as if you'll need to check the moisture level of the base (hull) laminate itself also. Inside & out, in several spots.
Assuming it's okay, which we're rooting for, when you
rebuild the stringers, you might consider using materials immune to
water ingress, or close there to. G-10,
Epoxy MicroLam, other H2O impervious structural synthetics, & or metals.
- Just take care not to over do it, or create any significant hard spots.
That & take a good look @ the structure of the flooring(s) AKA
Keel Support Structure, & decide if perhaps it's worth beefing it up a bit, prior to
epoxy sealing it. The sealing being so that this doesn't happen down the road again.
Good luck
PS: And aside from the usual knowledge resources, there's a few
Cal Groups over on Yahoo