Let’s start by defining the Gallimaufry itself, then see who we’ll find there.
The Floating Library
The Gallimaufry is a floating city-state built atop an enormous whale-turtle-thing. The purpose of the Gallimaufry is the retention of knowledge in the face of the Archmagus’ empire and its goals of control. The librarians collect texts and materials from all over the world. They index their acquisitions as cards in an ever-expanding filing system - the Ouroboros, capable of expanding to any necessary length as more cards are added.
The Gallimaufry itself began life as a small fleet of ships that sailed with the whale-turtle-thing. Perhaps selfishly, they hoped that if they were attacked, a stray shot might anger the creature and cause it to direct its wrath at the attackers. But in time they seemingly secured its blessing to actually come aboard, and the ships were abandoned for a complex, tightly bound network of houses, hallways, ladders, and more atop its enormous shell.
The whale-turtle-thing alternates between swimming sedately and floating in place. As a magical being, it seeks out places in the sea where elemental magic is strongest, anchors itself over those places, and soaks it all up. During these times, it can hibernate for days or weeks. The rest of the time, it goes wherever its instincts dictate. Needless to say, this slightly complicates the task of journeymen who want to return to the mobile island, but there are ways.
It isn’t clear whether the whale-turtle-thing really communicates with anyone aboard or not. What is known is that there’s a blessing all around its body - people can dive into the water and breathe it as though it were air. If that blessing is withdrawn, the librarians say, the whale-turtle-thing has become displeased.
The city itself is governed (to the extent that it can be, or must be) by a council of librarians. Citizens may take civil-service examinations yearly. Those who meet a minimum ranking become candidates for the council. Half the council’s members are elected, while the other half (plus a single tie-breaker) are chosen at random from the candidacy pool. Council members serve for a term of three years. Rather than consecutive terms of service, council members must leave office after their term, but may return after a full term has passed. Few choose this option, as council service is considered a tedious chore compared to scholarship.
Aside from librarians, the city has its share of ordinary workers and citizens - parents, chefs, tailors, fishers, and so on. The city’s economy is supplemented by trade with ports it comes close to, but of course the whale-turtle-thing’s wayward navigation makes reliable trade routes a challenge.
Citizens of Note
Any of these characters could be on the council - or just ordinary folk Mizzle might have interacted with. Their relative political power depends on what you want them to be able to do.
Any or all of these faces could be either an antagonist or friendly supporting character. Fyodor can hate Mizzle for destroying a book - or be guardedly grateful that the boy went to such pains to replace it. Atalya could be selling the city’s most prized treasures to outsiders - or bringing back some vital tome that will save the day. And so on.
Fyodor - the Conservative. An excellent scholar with a brilliant mind. Sees the purpose of the Gallimaufry as sacred - it’s better for books to be preserved than to be read. Except for useless or dangerous books, burn those for heat during the winter. Prefers to spend all day polishing and perfecting the cataloging system.
Serif - the Dilettante. A scholar with a perfect memory and a knack for cross-referencing seemingly unrelated texts. Wants the Gallimaufry to have a copy of every book in the world - but regretfully understands the whale-turtle-thing can only hold so much. Starts a new hobby every few months.
Atalya - the Book Buyer. An itinerant for the Gallimaufry, she travels the world buying books and returning with them. Not above trickery, theft, or worse dirty tricks to obtain what she’s after, which is something of an open secret among the senior librarians. Suspected of stealing from the library’s own rarest stocks to sell to outsiders, but nothing’s been proven. Has a face you can always tell is up to something, but you can never tell just what.
Carlyle - the Non-Librarian. A full-time chef. Known for an encyclopedic knowledge of the world’s spices. Won’t make you exactly what you ask for, but will take vague requests - “if you know exactly what you want, you can make it yourself!”. Knows a little about a lot, due to a lifetime of listening in on librarians’ conversations.
Xenami - the Weirdo. Typical of certain librarians, who hyperfixate on some specific topic in the library. Her obsession could be anything, but it’s definitely something. Listening to you is just her way of mentally drafting what else to say about her subject, but she does at least listen. Some ultra-conventional genre (adventure, romance, historical, etc.) is her guilty pleasure, but she’d much rather talk about her one weird thing.