Hachigatsu wrote:
This is from a 1990s issue of "The Official Godzilla Magazine", published by Keibunsha (and authorized by Toho).

August,

 It's from earlier than that. I don't doubt that it was also printed in that magazine, but the book I scanned it from came out sometime between 1975 & 1984. The last film indicated in it is Terror Of Mechagodzilla, so it seems Toho was putting this out as official history well before the Heisei era.
 There's also some interesting artwork in this book that I'll be posting in another thread.