Adding a couple wood slats might be a good idea for strength and to give it a piratey look,
There are places that sell the hinges and locks, but they are pretty pricey, unless you are restoring something.
madPete
Here is some food for thought...
We have a civil war era trunk as in the link below. On ours the main section/sides of wood are covered in painted canvas (except for the Oak slats). That would be easy enough to do though I can't vouch that it would be entirely period correct
http://www.brettunsvillage.com/trunks/forsale/t863.html
Have fun what ever you do with it!
madPete