Yeah, Google search "parave gelt." That will turn up dairy free chocolate coins intended for Hannukah, but they make great vegan Pirate treasure! That was what we used as party loot at my daughter's pirate party. (Here's a picture of the cake I made for it. I'm inordinately proud of it: http://i275.photobucket.com/albums/j...uploadcake.jpg)
Oh, and the veggie flavor Pirate Booty is vegan, too.
I don't have an answer as to where to find vegan chocolate in foil (other than mail order) but I just wanted to comment and tell you that you are awesome for even trying to find vegan treats so that child can participate in the fun!