The Castle in the Attic

From Author Wars - https://authorwars.com/publications/the-castle-in-the-attic-570062.html

Overview:

Title: The Castle in the Attic
Author: Elizabeth Winthrop
Year: 1992
ISBN-10: 0862783070
Publisher: The O'Brien Press
Price: £3.99
Pages: 179
Binding: Trade Paperback
Type: Novel
Title Reference: The Castle in the Attic
Notes:
OCLC: Source gives ISBN-10 and ISBN-13, maybe a later printing Same true of Amazon US and UK as of 2016-05-10, both as 1993-11-01

Price and confirmation of year from Irish Times 1992-12-19 pA9 "Flying Through Time" column on new time-travel books

As of 2016-05-11 OBrien.ie shows this cover image and ISBN-13, size 19.6 mm, price €6.95, "Rights held: Ireland, English only"