According to Don Markstein's Toonopedia,
[Alex] Raymond joined the Marines in 1944, and Jungle Jim never again looked as good. From a succession of unsigned artists, John Mayo eventually emerged. His most notable credit seems to be a strip called Future Eye, which was scripted by Jerry Siegel (co-creator of Superman), and which McClure Syndicate (School Days) launched in 1952 or '53 and folded in 1953 or '54. In 1948, Paul Norris (co-creator of DC Comics' Aquaman, TNT & Dan the Dyna-Mite, and Darwin Jones) took over. He kept it until 1952, when he began his long association with Brick Bradford, after which Jungle Jim was again drawn by Diverse Hands.
This is also reported elsewhere, though the wording is similar enough that they are probably all paraphrased from the same place. I had always thought that Austin Briggs followed Raymond on Jungle Jim. The art sure looks by the same person to me. I can find only two credits in GCD for John Mayo. One is a single page filler in Football Thrills (Ziff Davis) which I've never seen so I have no idea what his art looks like.
The other is as an inker over Austin Briggs in the Kitchen Sink Flash Gordon reprint book #6 "Austin Briggs continues with inks by John Mayo for first four Sundays May 7, 1944- May 28, 1944, After this Briggs did both pencils and inks."
Any thoughts?
