Where can I locate the letter J.R.R. Tolkien wrote to A.A. Milne?

Question

Where can I locate the letter J.R.R. Tolkien wrote to A.A. Milne, the author of Winnie the Pooh?

The web page Creator / J. R. R. Tolkien on TV Tropes claims far far down that Tolkien once wrote a strongly worded letter to A.A. Milne complaining about his stage adaption of Wind in the Willows, which it seems Tolkien had much disliked. I would really really like to find this letter. It would be fantastic for my essay.

Unfortunately, I can't. Does anyone have a lead on where I might locate it?

(The tropes edit history dead ends, so I can't ask the person who first wrote it. I'm not able to travel to an archive.)

Answer 1

The TV Tropes editor was probably thinking of the following passage from Tolkien’s notes to his essay ‘On Fairy-Stories’:

There is no suggestion of dream in The Wind in the Willows. ‘The Mole had been working very hard all the morning, spring-cleaning his little house.’ So it begins, and that correct tone is maintained. It is all the more remarkable that A. A. Milne, so great an admirer of this excellent book, should have prefaced to his dramatized version a ‘whimsical’ opening in which a child is seen telephoning with a daffodil. Or perhaps it is not very remarkable, for a perceptive admirer (as distinct from a great admirer) of the book would never have attempted to dramatize it. Naturally only the simpler ingredients, the pantomime, and the satiric beast-fable elements, are capable of presentation in this form. The play is, on the lower level of drama, tolerably good fun, especially for those who have not read the book; but some children that I took to see Toad of Toad Hall, brought away as their chief memory nausea at the opening. For the rest they preferred their recollections of the book.

_{J. R. R. Tolkien (1947). ‘On Fairy-Stories’. In C. S. Lewis, ed. (1947). Essays presented to Charles Williams. Oxford University Press.}

This essay has appeared in many collections, including Tree and Leaf (1964), The Tolkien Reader (1966), and The Monsters and the Critics (1983).