I would take it apart, and glue it back together from the inside first. Use a strip inside as well as the outside. Just do the inside first though. Do you use rare earth magnets to clamp down parts when gluing them together? If not, I would recommend it highly. Also gat some hand clamps for the ends, to help keep everything together while the glue dries.
Also, make sure you cuts are straight. If they curve, it will be harder to lineup the edges.