Peter Thomas says that the project started simply:
One day I thought to myself, "I love to make books and I love to play the ukulele. Can I put these two loves together? Can I make a book out of a uke?"
He and his wife Donna proceeded to make one. Thus began their life's work: to turn book making into an inventive art. Most commonly they build books within the bodies of ukuleles, but they also make miniature books for earrings and books within the bodies of old accordions.
The Thomases also teach classes on book art and exhibit their work. Mostly the wander, traveling across the country constantly in their vargo--that's a gypsy wagon. Fine Books & Collections magazine explains:
The Thomases seem to embrace the old saying about life being a journey, not a destination. The couple spent their early years exhibiting papermaking and bookbinding techniques at California Renaissance Faires. From running a private press, to experimenting with and producing a rich range of museum-quality handcrafted books, to being gypsy artists, it has been a long, and not always straight path for them. “You know the Tarot? I think my card is the Fool, or the Wise Man and the Fool, two steps forwards and one back. Or Mr. Magoo, walking along and walking off a bridge but landing on a moving truck, then being dumped into a river, landing on a barge,” joked Peter Thomas. “When I began I never attempted—or was tempted—to imagine the future. I was too busy doing what I was doing. Learning to make paper. Learning to print better. Gaining my aesthetic voice. Now that I am in the future, I am just trying to make things that are beautiful and bring joy to the beholder,” he added.
-via Messy Nessy Chic (content warning: nude J.D. Salinger)