I keep a stock of belly boards, ready to decorate and personalise! Every time I have made one the receiver has been thrilled, whatever age they are! The wood patterns are different each time but the shape and dimensions remain the same.
Each board is laminated from two sheets of Paulownia and Red Cedar with a layer of epoxy and glass in the middle. The deck and bottom is then coated with epoxy, sanded and then finished matt or gloss. This is nothing like a bent piece of plywood, it should last a lifetime!