To return briefly to the original question, Dick Greenhaus mentioned in another discussion about the song a couple of years ago that "Sylvest" was first published in 1908 as "MY BRUDDA SYLVEST, a stage-Italian dialect number that referred to the Spanish-American War": I'd add that sheet-music of what is presumably the original song is available at  The Lester Levy Collection of Sheet Music;  details are:

MY BRUDDA SYLVEST; Words by Jesse Lasky. Music by Fred Fischer; Fred Fischer Music Pub. Co., 1431-33 Broadway, 1908.  Three pages of score, with illustrated cover: MY BRUDDA SYLVEST.

Malcolm