One artist we thought we could name immediately was the penciller of "The Quicksilver Kid" in Superman 26 (Jan-Feb/44). He sneaked his name in on a wanted poster as "Killer Riss"—and as we could see from the Who's Who, Pete Riss had indeed worked on Superman in the Forties.
When Rich circulated his Superman Artists Guide, the feedback told us that we had mixed up Pete Riss with Sam Citron. Riss was a friend of Citron's, and that poster was an in-joke, not a signature sneak, we heard.
The credited work that Sam Citron did later for Gilberton, ACG, and Warren showed a hugely improved art style, but then, anyone can improve in ten or twenty years. In his revision of the Guide, Rich admitted our mistake, and we identified that artist as Sam Citron on similar Superman stories.
From the evidence I've seen since, we were right the first time. Mid-1940s work with an actual Riss credit line is closest to the style of this Superman artist than to any other.
Riss is credited with the Millie art on the intro page of Timely's Millie the Model 8 (Oct/47)—the artists of the Willie and Rusty back-ups go uncredited, as do the issue's writer or writers.
The Superman art and Millie art share a stiffness in the figures. I'm showing panels from the Superman story "Haircut—and a Close Shave" in Action 96 (May/46), attributed nowadays to Sam Citron (not credited to anyone other than Jerry Siegel and Joe Shuster in the creators' byline, of course). The artist of both stories notably treats arms as sticks and elbows mostly as hinges that work only on the plane of the page. The Millie panels are from #8's story "The Model of the Golden West"; compare the arm of the cowboy in the lower left Millie corner with that of the mustached man in the panel from "Haircut."
On Millie 7 (Aug/47) Pete Riss shares the credit for Millie art with Ken Bald; I'd say Riss pencilled the first and third stories in #7 and Bald pencilled the second and fourth. I believe one uncredited inker worked on every Millie story in both issues. (On other Timely comics' intro pages, the two artists listed, such as Mike Sekowsky and Joe Giella, were indeed penciller and inker. Was Stan Lee being inconsistent? Yes.) Bald, like the later Citron, has a better grasp of anatomy than Riss; and he gives some of his walk-on characters faces in a style unlike those in Riss's limited repertoire.
Comparing elbows again, this time from #7's "Millie's Music Maker," note the similarity of the Superman emcee's and the Millie band-leader's (in the center of the panel):
The strong Millie inker certainly submerges the penciller, but the only similarities I can find at all to any Superman artist are to the one presently IDed as "Sam Citron."
I feel Pete Riss did in fact sneak his own name on that wanted poster, and drew quite a few Superman stories (and Lois Lane back-ups) in the style of "Haircut." Whether the few stories now attributed to Riss are actually by Citron is a good question!