Wing should be fine from factory for training. If it were me, I'd join it with some 30 minute epoxy. Mix up a bunch, and coat both sides of the wing liberally. Get a bunch down into the joiner hole (I'm assuming it uses a metal rod) and have some masking tape ready. Join both sides, if you used enough epoxy it will ooze out from between the two. Check alignment, then run a couple pieces of tape to hold them together. check alignment again, then stand them up in a corner and let them cure for a good 12 hours. Check periodically to wipe up any epoxy that runs out of the joint. I don't think they'd need to be fiberglassed at this point.

Andy