Suzanne Watkins found this quote from a 1910 newspaper:

The Post-Standard
Syracuse, New York
Wednesday, October 26, 1910

His excuse is akin to the statement of the Shakespearian scholar who,
having investigated for many years the question of the authorship of
Shakespeare, finally announced that they were not written by Shakespeare,
but by another man of the same name.

   She also found this from Twain in 1900 (on Homer):

"Homer's writings are Homer's Essays Virgil the Aneid and Paradise lost
some people say that these poems were not written by Homer but by another
man of the same name. " - Mark Twain, English As She is Taught (Boston:
Mutual Book Co., 1900) 23

Fred Shapiro
Yale Law School