There are two songs with the name "Diamond Joe" in the DT, and a second version of one.
"Diamond Joe 3" is a party song, Diamond Joe 2 is the silly reworking of the song collected by Lomax, and "Diamond Joe" is the original song as collected by Lomax.

As Art Thieme says, there is the third song collected at Parchman Farms about the steamboat "Diamond Jo." Thread 59040 has notes on this one (Thieme and Stewie both posted in that thread). Richie commented in thread 54404.
Seems to me there should be a fuller version somewhere.

59040: Diamond Jo
54404: Steamboat Coonjine Songs