Ok, so it may be a cheap effect in terms of how foiling can be produced by laser printing black onto white paper then putting it through a laminate pocket fed via the machine. Then it come out all shiny. Magic. It was also a turning point for the brief, as I finally decided it was definitely a good idea to go along with it since it looks so damn good on page and would contribute well to the project. It would match the map, as well as giving the book a particularly professional look. When the book ages it would gain t hat fantastic grainy effect that I so desire!
Here are the foil results, sorry for the terrible photos.