if you've got the courage, there are photo etch piano hinges available. seems like they go together pretty easy -
https://www.youtube.com/watch?v=p38PUBZFdsY&list=UUOHpekq5a9k31BvF3I57yCg
https://www.youtube.com/watch?v=h3bqKP6UFKQ&index=27&list=UUOHpekq5a9k31BvF3I57yCg