Last summer a made this treasure box. It took me ages but I am very happy with the result. In the box a hide my treasures. Mostly gifts and things I have memories with. A few flags from land I've been, some medals, a tooth from a cow I found, my first bib, things like that. I hope that it's full one day.
I made the handles and stuff look old, so the box would look like an old one. To make it rust put it in the BBQ so the coating falls off, make it wet, lay it in the rain for a long time and varnish it when it looks good to you. Use matte varnish, you don't want an 'old' handle to shine. If you don't varnish it, it might stain your clothes.