Re: Centerboard damage.
Herlihy's suggestion sounds reasonable. After cleaning out all the loose stuff and letting everything dry out (perhaps giving it some help with hot air) it shouldn't be too difficult to refill with goop and and re-glass the joint while holding the two sides in place. Material may cost less than $100, add a couple of hours of work, and you'll be back in business. Be sure to grease things while they're accessible.