There have been many hundreds of tunebooks published since William Billings started the ball rolling. Few remain in print or readily available, however; Warren Steele provides a listing of tunebooks still in print (or only recently out of print).
Some tunebooks are available in image format on the internet. I have been resetting tunes from Supply Belcher's Harmony of Maine and John Norman's Federal Harmony. I have recently completed a "pretty good draft" of Ananias Davisson's Supplement to the Kentucky Harmony and would appreciate your comments/corrections.
I use Lilypond to set these tunes. Lilypond is free and produces very high quality, consistent results. Shapenote support was substantially improved with version 2.13.20, so be sure to install that version (or higher).
New Tunes in the shapenote tradition are now being published in a new periodical, The Trumpet, three times a year.
In memoriam for George Sielier, I'm posting two tunes written for the New Jersey Convention, which George and Jean helped to found and lead.