Originally Posted by Wonder Boy
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I don't feel like tracking them down right now, but I recall these pin-up pages appearing in the Kirby FF annuals.


[Linked Image from i.pinimg.com]

This first pin-up looks like the FF figures from the opening splash page of FANTASTIC FOUR 78, Sept 1968, only with just the FF figures, and the background removed, with a new background and text added in.
https://readcomiconline.li/Comic/Fantastic-Four-1961/Issue-78?id=27174


I was recently looking through MARVEL TRIPLE ACTION 3, June 1972, and that appears to be the first place this FF pin-up appears, that omits the background from the opening page of FF 78, and adds a cloud background.
https://readallcomics.com/marvel-triple-action-v1-003/

As compared to the original FF 78 version, on page 1 :
https://readallcomics.com/fantastic-four-v1-078/


Originally Posted by WB
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[Linked Image from i.pinimg.com]

The original page for this second one was recenttly listed on Ebay, as a "1963 Marvelmania pin-up"

So if accurate, not printed in a Marvel comic, a pin-up page mailed out exclusively to Marvel fan club members.

A slightly altered version of this pin-up appears in a 6-page "FF family photos" section in MARVEL'S GREATEST COMICS 29, Dec 1970 :