THe Weird Tales ones are PD <Conan>
Copyrights were never renewed.
L. Sprage De Camp/Lin Carter tweaked the stories <re-edited> and wrote others to fill in holes and put them in a chronology- which are the ones I grew up with <the books with the Franzetta covers> and they are CC'd.
The company CPI own's <or owned as they were bought out> the word "Conan" but not the original Stories.
Sorry for the Conan rant there-LOL
go to Gutenburg- for PD stuff and you will be amazed! http://www.gutenberg.net.au/sfproject.html