Hi I used the same wood. I would not use 'glass. And I chiseled out to one half the depth. A replacement rib is pretty simple task. I'd do that unless there is a real good reason to keep the broken rib. My backside rib repairs were on 3/8" thick ribs. I thought of doing it on 5/16 but it seemed pretty thin. No reason you can't use a stronger wood I suppose.