Who wrote the “Lost Sherlock Holmes Story”?

The other day I had written about a newly rediscovered and supposedly ACD-authored Sherlock-Holmes-Story.

Now, though, the people of “I hear of Sherlock Everywhere” make a good point for it being a pastiche after all…  a very early form of fanfiction, if you will.

(And just for the record: I love good fanfic!)