The Magical Cupboard

From Author Wars - https://authorwars.com/publications/the-magical-cupboard-269880.html

Overview:

Title: The Magical Cupboard
Author: Jane Louise Curry
Year: 1976
ISBN-10: 0689500599
Publisher: Margaret K. McElderry / Atheneum
Price: $6.95
Pages: 138
Binding: Hardcover
Type: Novel
Title Reference: The Magical Cupboard
Notes: 1st ed. Publisher, page-count, and credits from library records: LCCN: 75043892, with Summary -- ISBN 0-689-50059-0 (bad checksum) OCLC: 1975297 -- no ISBN

The valid ISBN entered here is from Amazon, sometime. Publ date, price, and cover image probably from Amazon, same time.

Amazon US 2017-03-17 for this ISBN gives "Hardcover" and "Encore Editions; First edition (August 1976)" Amazon UK similarly