I think I'd take a completely different approach. Sure you could re-hinge the existing elevators but it wouldn't take hardly any time at all to just lay some waxed paper over them, grab some balsa sticks and a razor saw & make new ones. If the stab is glued in that might be tougher to rebuild but not impossible if you could somehow remove it. You could also likely figure out away to replace the TE on the existing stab. I've done this a lot on damaged ARF's rather than trying to repair damage to simply constructed sections like these elevators.

I'm not necessarily saying it is the first method to choose but it might be an option if re-hinging isn't easy.