Diamond Comic Distributors has added another exclusive publisher to the growing list of companies that it represents to mainstream bookstores as well as comic shops.  Archangel Studios, which publishes The Red Star and which recently split from Image Comics (see 'Turnover At Image'), has chosen Diamond as its exclusive distributor to all channels except the newsstand.  Diamond, which distributes Marvel books to mainstream bookstores, has just added several new clients to the list of publishers that it represents to the book trade (see 'Comics One Moves To Diamond For Bookstore Distribution').