There is a PDF scan of a c.1930 chapbook of the song here. The text ends with this comment: Note: The editors wish it distinctly understood that they have been unable to establish that the foregoing lines are from the pen of Rudyard Kipling—in fact, no evidence is available that he has had any part whatsoever in its composition. This would seem, once and for all, to dispose of the persistent report that, but for this ballad, he would today be Poet Laureate of England. This doesn't absolutely guarantee that he wasn't, of course...but people have apparently been debunking the rumor (or rumour, if you prefer) for nearly 80 years!