It's frustrating for me, as an ex-librarian, that the book does not have the usual publication details on the next page after the title page. In most other books the original publication date, and the date of that specific edition would be stated but my book only shows that that edition was published in 1979. The front cover, which is the distinctive yellow cover, is a copy of the original cover and has a lot of detail on it but the date of publication is not shown there either.
I have owned my copy for at least 40 years. It is a great resource and I fully appreciate the work that O'Neill did in compiling all of those tunes.
Oh no! I just read the text on the back cover of the book and hidden in that lovely old font is the statement, "This collection was published in 1903, as a result of Capt Francis O'Neill and many traditional musicians attending the Chicago Music Club, circa (1890-1900)."
So the publication date was there all along, hiding in plain sight.