STAR SPANGLED COMICS #38, 1944, was from the era when Kirby was in the army, and only did covers for the DC/National books. STAR SPANGLED was still running the Newsboy Legion as the main feature, as it has been since #7, and this is a fun wartime patriotic style cover.
RAWHIDE KID #33, 1963, is the first issue Kirby did just the cover for, after introducing the new Kid in #17. Good western cover.
NOVA #5, 1977, inked by Frank Giacoia, another one of those covers done in that era for non-Kirby characters. I kind of like Nova's design, it's very compatable with the Kirby look. The "Earth-Shaker" villain seems a bit ridiculous, though. Looks like good goofy fun, I guess.