The Elmira Center for Mark Twain Studies published a small book
about the Pilot's Association (and the later Western Boatman's
Benevolent Association) in its Quarry Farm Volume series:
Edgar M. Branch, _Mark Twain and the Starchy Boys_ (Elmira: Elmira
Center for Mark Twain Studies, 1992).
It can still be ordered from the Center. See the Quarry Farm Volumes
section at the bottom of its publication list at: