In 2006, I mentioned the publication of David Mead's Reel History, a comprehensive softback reference guide to American coin-operated machines from 1894 to 1980 with 425 black and white photographs. Six years later we have, at last, another new book on the subject from Tom Gustwiller, who previously authored For Amusement Only, a black and white hardback devoted to trade stimulators and other American countertop games.
Happily, Reel Amusement, is in full colour coffee-table format and covers over 450 machines (some never seen in print before). It even features the odd British game, such as Ell's Colonial Shooting Range. As with his previous book, the author seems to have taken a self-publication / self-distribution approach. As far as I'm aware, it is currently only available from the author (call 419-234-6133) or via his eBay sales (for $75 plus shipping).