I scanned these awhile back but I can't recall now which issue of SHOWCASE they were in. Doesn't really matter, I guess, because I'm pretty sure they were reprints there from REAL FACT COMICS ten-fifteen years earlier. Either way, it's two color pages by Virgil Finlay, one of the great pulp and sci-fi illustrators (and a favorite of at least a couple of my readers!). Finlay died in 1971 just as his work was being rediscovered so he probably didn't know just how revered he was by fans even then.
12 hours ago