Without a doubt, the two biggest tidal waves of American Godzilla merchandise from my youth, were: 1978 (to promote the Hanna-Barbera series, etc.) and 1985 (to promote, of course, GODZILLA 1985). Today's item belongs to that second group.
What we have here is a lovely 24" x 36" poster, by an artist named Aldrich. It was produced by Banning Enterprises, and, much like today's posters, came rolled up in a plastic sleeve:
Inside was a flyer that included a surprisingly accurate history of Godzilla. You really have to give them credit; aside from misspelling "Serizawa," they did a great job:
On the back, an advertisement for THE GODZILLA FAN CLUB, where, for the cost of only $2.50, you would get a button and a year's subscription to THE GODZILLA GAZETTE! It would be interesting to know whatever became of this endeavor...I don't see how $2.50 was enough for a year's worth of newsletters, even back in 1985.