a very simple version is in "The Banjo Player's Songbook" by Tim Jumper Published by Oak Publications.See the Coo Coo on page 130. Chords used are Gm, and F with the banjo tuned to Gm. (g D G Bflat D)
A more complicated version with an A and B part is in Clawhammer Style Banjo by Ken Perlman on page 163.
JAB