Indeed, it's a stamped halfpenny. With regard to the book, Dr Brunk published: "Identifying Coins Medals & Tokens: Late Antiquity to Modern Times" in the 1990s. However, I suspect that you will want: "Merchant and Privately Countermarked Coins: Advertising on the World's Smallest Billboards" published in 2003. Although it looks as if he specialises in North American tokens. It can be quite expensive to acquire, by the looks of it.