Yearling, New York, 1984, reprint.  ISBN 0-440-49276-9.  Trade soft cover, 140 pages.  Unread copy; light edge wear and bit of cover wear; tight binding; interior clean and unmarked with tanning pages; black & white illustrations by Richard Lauter.  ‘Peter is thrilled that Grandpa is coming to live with his family.  That is, until Grandpa moves right into Peter’s room, forcing him upstairs.  Peter loves his grandpa but wants his room back.  He has no choice but to declare war!  With the help of his friends, Peter devises outrageous plans to make Grandpa surrender the room.  But Grandpa is tougher than he looks.  Rather than give in, Grandpa plans to get even.  They used to be such great pals.  Has their war gone too far?’ (from rear wrap)