You can buy the plane online at www.aeroacemods.com for $30 + whatever they charge for shipping.

They also have some advice on extending the antenna and will send a bit of antenna wire to you for free. I assume it comes with installation instructions, but I don't know.

By the way, removing the tail requires quite a bit of force and it probably will never be quite the same afterward. It seems to be glued in place, not just taped. On most of the planes you can see the end of the antenna tucked in beside the vertical tail fin if you look very closely.