Masato - I saw that "Uncle Ned" at Levy, too. I think it's just the Foster song, without attribution, translated into not-so-thick dialect.

There's an interesting commentary on "Uncle Ned" in A Treasury of Stephen Foster (Random House, 1946):

"The Knights of the S.T." (a small social group that met in Foster's home) liked "Lou'siana Belle" so much that Stephen was encouraged to write another song for the next meeting. He came with the manuscript in his pocket, put it on the piano and invited his friends to sing with him Old Uncle Ned.
This was one of the group of songs, along with "Oh! Susanna," which Stephen gave to W. C. Peters, either for $100 for the lot or as an outright present, and which Peters published and copyrighted from his Louisville establishment on December 30, 1848.
Its popularity was never as great as that of "Oh! Susanna," yet it became a wide favorite. From the drawing rooms of Cincinnati, it spread to the concert halls of the city and then, inevitably, to the current minstrel shows.
It is said that the descriptive line of the poem: "his fingers were long like the cane in the brake," was so vivid and picturesque that Southerners would not believe that the verses were written by a Northerner who had never seen a cane brake. In 1852 an anonymous writer remarked in a periodical of the time, Albany State Register:

There is something in the melodious "Uncle Ned" that goes directly to the heart, and makes Italian trills seem tame. As for poor "Uncle Ned," so sadly denuded of his wool, God bless that fine old colored gentleman, who, we have been assured so often, has "gone where the good darkies go."

Foster's songs became known throughout the world soon after they were published in America, and they were translated into many languages. In Leipzig the firm of Max Brockhaus issued a series of "Negerlieder" which included Old Folks at Home ("Heimweh"), My Old Kentucky Home ("Leb' wohl, Kentucky-Land"), O! Susanna, and Old Uncle Ned ("Onkel
Ned").

ONKEL NED
(Stephen C. Foster)

1. War einst em alter Neger, Genannt der Onkel Ned,
Dass er starb, das ist lange schon her,
Mit Freuden sagte der Welt er Valet,
Denn der Ruhe bedurfte er sehr.
Legt drum die Spaten aus der Hand!
CHORUS: Hängt eure Fiedeln an die Wand!
Denkt zurück an den alten Ned,
Der langst seine Ruhe schon fand!
Denkt zurück an den alten Ned,
Der langst seine Ruhe schon fand.

2. Der Alte Ned hatte kein Haar auf dem Kopf,
Seine Wolle, die fehite ihm sehr,
Es hatt' keine Zähne der arme alte Tropf
Und das Beissen, das fiel ihm drum schwer.
Legt eure Spaten aus der Hand:
CHORUS

3. Der Tod Onkel Neds der bereitete Schmerz
Seinem Herrn, denn er trauerte tief.
Seiner Herrin ging's wie em Stich durch das Herz,
Aus den Augen manch' Thränlein ihr lief.
Legt drum die Spaten aus der fland!
CHORUS