Selleys Araldite Super Strength Epoxy Adhesive will be ideal for this repair. For the best result try and remove any old adhesive first. This will allow the glue to bond well to the timber surfaces. After gluing, clamp the joint and allow 24 hours for the glue to cure. You can also use Aquadhere Durabond Polyurethane wood working glue which has excellent gap-filling properties.