There is a version of Way OUt West in Kansas here attributed to Carson Robinson - 1924

regarding the graveyard/mule one - I found this:
Title: Go 'long, mule.
First Line: I've got a mule, he's such a fool
Chorus: Go 'long mule, don't you roll dem eyes, you can change a fool but a daw gone mule is a mule until he dies
Music by: Creamer, Henry, and Robert King.
Words by:
P/P/D: New York : Shapiro, Bernstein & Co, c1924. Location: SPC, KIRK PS 1923-1929