Cracks perpendicular to the backing is not a good sign because you don't know how deep they run.
About the only thing that can be done is to sand the edge to bare wood using 220 grit sand paper, blow out the sawdust, then use a water thin super glue and let it soak into the crack until it puddles up. Let it dry for about 10 minutes or so, then lightly sand the edge with 220 grit sand paper and seal it with a clear coating.
If you attempt this...... be very careful with that thin superglue... It can run everywhere instantly and ruin the finish on your limbs.... Use masking tape so it doesn't get on the limbs belly or back glass.
After doing that, you may want to let it set for a couple days in a warm temp before testing it.... It's either going to work.... or its not.... Kirk