This is an interesting discussion. The broader question is about the
copyright status of unpublished works. As we all (certainly) know, here,
SLC died in 1910-- and didn't write much more after Dec 1909.

But not everything was unreleased before he died. In fact, there was a lot
of text. Much of the Autobiography, the pieces of #44, The Mysterious
Stranger, etc.

http://www.copyright.gov/pr/pdomain.html
"Certain Unpublished, Unregistered Works Enter Public Domain"

(This copyright thing is what my employer manages, so I know a little about
it.)

Our boy, of course, argued for perpetual copyright. He didn't get it. Also
-- the copyright status of articles and short pieces appearing in journals
and newspapers was different in his day. Mostly, they lacked copyright
unless and until they were collected into a book.

DDD