If the dihedral brace is flat against shear webbing giving a fair amount of wood to drill into, you might be able to drill 2 holes (one near the top and one near the bottom) and insert a couple dowels to use as wing joiners. If you can get em to fit together with some wood holding them, all you'd need is a thin strip of fiberglass down the middle to reinforce it. Of course, getting the angle right on those holes on both wings wouldn't be easy... And no matter how you do it you're going to be stripping some covering to apply glass.

Hobbico and the tower conglomerate seem to be pretty understanding people too. You might want to call and see if they'll give you a break on some replacement wings. If nothing else, they might be able to suggest a better fix.