If they're cheap enough, buy them for the hardware, & put new shells on them. Ply shells are cheap. The only value in this shell is the finish, & that's screwed anyhow. As for repair, you're going to be constantly fighting this drum if you're relying on the heads & hoops to keep it round. Just stuffing some glue into the gaps won't offer much in the way of strength. The only way to repair this drum to a satisfactory standard (& frankly, I wouldn't bother) is to place accurate formers to the inside of the shell, glue the joint, then use multiple ratchet straps to force the two sides of the crack together, such that you get a total bond across the crack surface area.