Rib replacement

1. Original steam bent ribs were one piece - gunwale to gunwale.
To avoid removing the deck, would two-peice ribs do? (butt at keelson)

2. If original ribs were 1/2" X 1", will 3/8" x 1 1/4" do?

 

It depends on the boat, but the usual answer is no. Some times you can overlap the ribs, so that they cross the centerline of the boat, typically out to the bilge stringer or darn near. It looks like interlocked fingers over the keel. Many boats are built this way initially, such as the White Canoe craft. What boat is it?