#1 left off the credits for the final story, "A Room Full of Changes," but—if you assumed the other credits were correct, as I'd say they are—you could work out from the list of contributors on the contents page that this was the one story written for the issue by Nicola Cuti, and that the artist was Ernie Colón.
In #2, the script for "Montezuma's Monster" was miscredited to Don Glut, but in the #3 letters page corrected it to R. Michael Rosen—when he pointed out the mistake. He was listed in #2's list of contributors.
#5 brings the miscredit that has been dutifully entered in the Grand Comics Database. The art on "The Craft of a Cat's Eye" is credited to John Fantucchio, like that of "Ghoul Girl" later in the issue. The artist team, under their collective pen name, is in the list of contributors: "Tony Williamsune," actually Bill Fraccio and Tony Tallarico. Critics may have moaned and groaned about their art—but that means it should be, at the very least, distinctive, doesn't it? The full page here is from "Cat's Eye" (the only story in the issue not signed, by the way) and the tier is from "Ghoul Girl."
In #9, the editors use a writer/artist's pen name, which is not a mistake on their part, but the GCD ought to credit "Alac Justice" as Jack Katz, identified as such by the Who's Who. If Katz's style is so hard to ID because he wasn't doing that much in mainstream comics at the time, can the same be said for #4's "David StClair" (meant for "St. Clair," I'd say, but misspelled "Sinclair" in the GCD)? Ernie Colón had stories under his own name for comparison's sake in issues 1, 2, and 7 as well as in Creepy and Eerie.
Speaking of pen names, let me return to one I mentioned: Tony Williamsune. On Vampirella, the GCD never mentions the penciller in that team of Tony and William: Bill Fraccio. One can see where the mistake comes from, since in #1 he's ghosting the pencils for Tony Tallarico, who takes the sole credit. But a look elsewhere gives more information about their styles. Gunmaster at Charlton gives a comparison of Fraccio's pencils under various inkers: not only Tallarico (#2) but Ernie Bache (#1, 3, 4), Vince Colletta (#87), and Frank McLaughlin (#89). (Yes, the numbering changed to take up another title's—it's Charlton.) #89 gives a credit line to Fraccio and McLaughlin. It repeats that credit in the bottom margin of a back-up story drawn by José Delbo—bringing me back to my original statement about the trustworthiness of credits.