The ribs can be glued back together if the crack is clean and there are no parts missing. I wouldn''t double the ribs unless they are at the root. Ribs in the middle of the wing are used more for creating the curve then structural reinforcement. Plus, a good glue joint should be just as strong as the surrounding wood. Most people add too much weight because they just double up everything. I subscribe to the practice of removing and replacing material damaged to the point of no return rather than doubling. Don''t take off the whole leading edge as a new piece can be spliced in. Cut out the broken edges at a very sharp angle. Then cut out the replacement to fit. The sharp angled cuts will give much more surface area to glue and will be very strong. Use wood glue for the leading edge replacement. Sand the joint and you won''t ever be able to notice it.

Remember, never use CA to sheet the wing. The CA won't sand as quickly as the surrounding wood (even with a sanding bar) and you will have ripples where the joints are.