Platypus, I’m afraid you're mistaken about the status of at least some CAS's copyrights, and are giving the Eldritch Dark community bad information that could potentially get someone in trouble if they believed you and tried to publish CAS's material without first obtaining the proper reprint licenses.
CAS's material that was copyrighted with him as the claimant lasted for 28 years after publication. When he died in 1961, his wife Carol inherited his copyrights. Before they expired, however,
she renewed the copyrights for an additional 28 years for at least three of his collections: "Nero and Other Poems", "Out of Space and Time", and "Lost Worlds". The U.S. Copyright Act of 1976 retroactively extended that copyright renewal period to 47 years, and the Sonny Bono Copyright Term Extension Act of 1998 extended it for yet another 20 years, for a total of 67 years. When Carol died, her son William Dorman inherited them, and the copyrights are still in effect until the 2030s:
• "Nero and Other Poems": published 1937, renewed 1964, expires in 2031
• "Out of Space and Time": published in 1942, renewed in 1970, expires in 2037
• "Lost Worlds": published in 1944, renewed in 1972, expires in 2039
While I can't say for sure about CAS's other material, the following stories and poems are absolutely, positively, 100% still legally under copyright, held by William Dorman:
STORIES
A Night in Malnéant
A Rendezvous in Averoigne
A Voyage to Sfanomoë
Necromancy in Naat
The Beast of Averoigne
The Chain of Aforgomon
The City of the Singing Flame
The Coming of the White Worm
The Dark Eidolon
The Death of Ilalotha
The Death of Malygris
The Demon of the Flower
The Door to Saturn
The Double Shadow
The Empire of the Necromancers
The End of the Story
The Flower-Women
The Gorgon
The Holiness of Azedarac
The Hunters from Beyond
The Isle of the Torturers
The Last Hieroglyph
The Last Incantation
The Letter from Mohaun Los / Flight into Super-Time
The Light from Beyond
The Maze of Maal Dweb
The Monster of the Prophecy
The Planet of the Dead
The Plutonian Drug
The Return of the Sorcerer
The Second Interment
The Seven Geases
The Tale of Satampra Zeiros
The Testament of Athammaus
The Uncharted Isle
The Vaults of Yoh-Vombis
The Weird of Avoosl Wuthoqquan
Ubbo-Sathla
Xeethra
POETRY
A Dream of Beauty
A Song of Dreams
Chant to Sirius
From the Crypts of Memory
Medusa
Nero
Outlanders
Retrospect and Forecast
Sadastor
The Eldritch Dark
The Shadows
The Song of a Comet
The Winds
To the Darkness
This includes at least four of the ten Averoigne stories. If Inpatient Press didn't obtain the permission of CAS's heirs (which, to the best of my knowledge, they have not), then they are in violation of the copyright.
Finally, Platypus, you've stated repeatedly (and rather forcefully so) that all of CAS's work is in the public domain, but you haven't offered us any proof. Why do you think that? Do you have any evidence or documentation to back up your claim? If so, please post it here. Thanks!