The name of the historical Pancho Villa (once prominent in U.S. newspapers) unfortunately rhymes with "gonorrhea," leading me to suspect that the name figured in the original text.

Why "ruptured cowboy"? Just bawdifying the first syllable of "rancho"?

Though "Alla en el rancho grande" was popularized in 1939 by both Bing Crosby and Gene Autry, it was published earlier in John and Alan Lomax's "American Ballads and Folk Songs" (1934) as a traditional border song. However, it had been copyrighted in 1927 by the music publisher Salvador Cabrera, with words and music credited to Silvano Ramos.