Wow, thanks for the deep and wide exploration of a song that caught my fancy, too. When I first heard the song, I thought it was about a red-headed woman and a big bay horse.... Don't know what 'hole in the wall' refers to, but it is an alternate title for the Ten Broeck song recorded by Sidney Robertson Cowell in Central Valley, California on September 3, 1939 and performed by Warde Ford. The link is -can I do this? - The Library of Congress American Memory and includes audio files. It is sung without accompaniment – Ford sings "John Parker John Parker, let go of the reins – ." Parker - Kypur - Piper - and the real jockey was apparently William Walker. Close. The National Museum of Racing and Hall of Fame site unfortunately does not mention Walker at all, but notes that the owner was Frank Harper, and the breeder was John Harper - that is closer to Kuiper - Piper, etc. Fascinating how the details are blurred as the spirit of a song builds and changes, depending on whose interpretation it is.

Regarding the original composer, according to Timothy at McSweeney's site: "Although Monroe takes songwriting creds, by most accounts, a banjo-playing Afro-American minstrel originally composed the ballad to commemorate a $10,000 horserace that took place on July 4, 1878 at Churchill Downs in Louisville, KY. (Compare with the broadside ballads of 18th-century Great Britain, several of which relate similar tales of racehorses named "Skewball" or "Old Kimball")." And whose accounts would that be? I haven't found them yet. That would be the thread to trace. There is something about the imagery and rhythm of these lines that seems African to me:

"Women's all a-laughing, children's all a-crying,
Men folks all a-hollin', old Tenbrooks a-flying.
Old Tenbrooks a-flying, Lord, old Tenbrooks a-flying."
   

Thank you Mudcat - Mary