This book was on the shelves of the library of my middle school in the early 60’s. I would find it by the cover, which I think showed a tree with a round door. Not unlike Hobbiton, the story was about small people and their society. They lived in hollow trees. The thing I remember best is that the individuals wore capes that matched the color of their front door.
Was it The Gammage Cup by Carol Kendall?
No – unfortunelately
is it Paulus and the Acornmen?
no
Is it “Loretta Mason Potts”?
no, but I think I will read this series 🙂
Palmer Cox’s “The Brownies: Their Book” or one of its sequels? https://archive.org/details/browniestheirboocoxp
Not this one either
“The Gammage Cup” had a sequel, “The Whisper of Glocken”. Maybe that one?
What about the Magic faraway tree? by Enid Blyton