Kirby was used heavily as a cover artist for the 1976 Marvel annuals.
THOR ANNUAL #5, 1976. John Verpoorten inks. You know, Odin and Zeus really should just fight their own battles rather than pitting their sons against each other.
AVENGERS ANNUAL #6, 1976. Frank Giacoia inks. Nice, but a bit cluttered. And Captain America fighting the US Army, that’s just wrong…
FANTASTIC FOUR ANNUAL #11, 1976. Joe Sinnott. The FF face off against the Invaders. That’s a fun looking cover, especially Ben vs. Namor and the battling Torches.
MARVEL TWO-IN-ONE ANNUAL #1, 1976. Joe Sinnott again. The Thing teams up with the Invaders spin-off group The Liberty Legion. I always like how Kirby draws those Golden Age and faux-Golden Age characters, and of course Ben Grimm is his signature character.
Kirby did two other covers for 1976 Marvel annuals, HULK, which was covered here, and CAPTAIN AMERICA, for which he also did the interiors.