From JJ Hartel's website:
"James Hartel has been making and playing banjos on and off since 1973 when he made a banjo for his 2 year old daughter. Jim has had access to a vast array of surviving early banjos through the generosity of banjo history experts, collectors of early musical instruments, and museums. He has documented the exact dimensions, construction techniques and detailed characteristics of each individual instrument that he replicates. Furthermore, he continues his research and fine tunes his banjos regularly so that they look and sound as much like the banjos of the early minstrel period as possible."