I've gotten lots of good ideas on how to get these ribs in. Thanks everyone! I think I will start by trying to work the ribs back into the mortises and put temporary lashings from the chine to the deck beam to hold the tension and keep them in place until the boat is shrunk and urethaned (as suggested by Mark). If that doesn't work, I will try one of the other good ideas that you all have so graciously provided. This board is great for problem-solving!

Thanks,

Linda