In the book, Fahrenheit 451, do you have a sense that there are other "book chapters" in other towns? What proof of this do you have?
As the previous educator has commented, there are definitely "book chapters" in other towns. We know this from Granger's dialogue in which he tells Montag about some of the towns involved in his resistance movement:
Chapter One of Thoreau's Walden in Green River. Chapter Two in Willow Farm, Maine.
We also get a sense of other "book chapters" when Granger talks about the number of people involved in this movement:
Thousands on the roads, the abandoned railtracks, tonight.
This high number suggests that multiple towns have men like Granger who have memorised chapters of a book or entire books. Unlike traditional resistance movements, which take action to overcome their adversary, Granger and his men simply wait for their knowledge to be called upon. They are waiting for the cities to be destroyed and for people to seek guidance from books. At this point, these men will come forward and recite what they have memorised for the benefit of future generations.
There are definitely other book chapters in other towns. When Granger is explaining their system of memorizing books, Montag asks him how many of people are involved in this endeavor. Granger explains that there are thousands on the roads and the abandoned railways. They look like bums on the outside, but they are libraries on the inside. He tells Montag that over a period of 20 years, they have developed a "network". (pg 153) He says that some of them live in small towns and tells of a town in Maryland in which 27 people have memorized the complete works of Bertrand Russell. Everyone is quietly waiting for the day when they can rewrite the books, but until then they will pass on their knowledge through their children.