it looks fixable, and i like your attitude.., 'not letting it go without a fight'
i had a handle (glued on) start to split much like yours has this morning. i glued it and then smeared the handle with glue and wrapped it tightly with para cord. it's drying now so i haven't tested it, but i doubt it will give me any more lip.
you could screw or daol it, but i wouldn't bother. i think the hemp/glue wrap will do it and then you wont have to hide the ugly signs of screwing or dowling.
i used techniglue, which i use for my glass bows and is something similar to smooth or the like. it is far stronger than the timber it is being used to hold together. mine lifted because the bow was a slight bend through the handle design, and was trying to pop the handle off. i have seen this a couple of times with glued on handles and surpose the pressures and ideas are the same for the stave bow.
good luck, i hope it can be resurrected!