Old Town homes inside the six blocks Hemingway walked: Duval, Whitehead, the lighthouse, the house with the cats.
The rule: the listing puts you in Old Town or names the landmarks. Not a ranking, and not every conch house in town.

Hemingway lived on Whitehead Street from 1931 to 1939 and wrote a good part of his best work in the studio over the carriage house. The neighborhood around it is still the neighborhood: gingerbread trim, porch swings, a lighthouse across the street, Duval two blocks over and loud.
Seven homes from two managers with their own booking sites. One names the Hemingway Home directly; the rest qualify on Old Town and Duval, which is the same six blocks. Each links to the manager; you book with them.
The Hemingway Home and Museum on Whitehead Street is open daily; the cats are real and there are a lot of them.