@mickbobcat
To my knowledge there were 17 versions of the "blue bomb" in English language. What does it say inside your book, how many pieces were printed?
The first editions had a circulation of 5,000,000 and 8,000,000 pieces.
In 1980/1981 there was a revised version, and the 1975 "prediction" was modified. This last version - besides your just bought version - shows very nicely the change of time at the JWs.