Unless you are really pressed for cash, I would not recommend stripping your trainer to put together your second plane. There will be "incidents" where you will need to repair your plane, and if you keep your trainer together, you can keep on flying during the repair. You will also have times when you just feel like you have lost your confidence and want to go back to the trainer for a refresher. Trainers are also great for competing in fun-fly activities, flying on floats, aerial photography, etc.

I know that in the original post, it sounded like the trainer is just not fun anymore, but I am pretty sure I will always keep mine around.