The Number of the Beast

From Author Wars - https://authorwars.com/publications/the-number-of-the-beast-198509.html

Overview:

Title: The Number of the Beast
Author: Robert A. Heinlein
Year: 1980
ISBN-10: 0450046753
Publisher: New English Library
Price: £2.95
Pages: 555+[1]
Binding: Paperback
Type: Novel
Title Reference: The Number of the Beast
Notes:
Definitely SAYS "First NEL paperback publication, January 1980", later editions qualify the statement with "NEL Open Market Edition January 1980" "Illustration: Gerald Grace" on back cover, no visible signature on the wraparound artwork