WorldCat (OCLC, below) reports 1972, the known year of the William Morrow 1st ed. as The Shark in the Window.
Amazon.com (ASIN) reports 1973, which is entered here as one-year delay is expected in publication of a paperback edition, by a new publisher under a new title.
Cover image from Amazon.com 2018-09-19 as "Paperback – 1973" and "Scholastic Book Services; First Printing edition (1973)"
Catalog ID from cover image
"1st printing September 1973" on copyright page of Archive.org copy.
