Exactly; Gutenberg/pgdp won't accept stuff published after ~1930 because it is too hard to clear copyright. In the case of an anthology mag you have overlapping copyrights of the mag and the authors of the stories.
It looks like the magazine itself didn't have the copyright renewed back when that was mandatory, so the pre-1964 issues are out of copyright as far as the magazine's own copyright goes (which is probably why archive.org feels comfortable putting them up). But yeah some subset of the individual stories are probably still copyrighted, so PG would avoid it.
The man on the cover is wearing one of those mirrors on his forehead that you often see in older photos of doctors. Thanks to Google and Wikipedia, I can now report what it is called ("head mirror") and what it was used for (to provide illumination for ear, nose, and throat exams). [1]
Just read Fredric Brown's Honeymoon in Hell in the November 1950 issue. Made me smile, gave me a little hope that perhaps we might all get on together after all.
Could never understand why Fredric Brown wasn't better known.
https://blog.archive.org/2012/04/26/downloading-in-bulk-usin...