[Mister Underhill]

Am I crazy? Is there anything mentioned in this (as Bb noted, quite clumsy) summary that even sounds new?

Tolkien states that his intent was ‘to write a story that would be "exciting" and readable, and give me scope for my personal pleasure in history, languages, and "landscape"’

Tolkien discusses similar motives -- in the Foreword, no less -- not to mention several published letters.

Tolkien rules out the allegorical reading of his books, remarking that he has ‘never found books on myths and symbolism attractive . for me they miss the point and destroy the object of their enquiry as surely as a vivisectionist destroys a cat or rabbit’

Tolkien's expressions of dislike for allegory and allegorical interpretation of LotR are legion.

Tolkien discusses at length how characters arise ‘out of the necessities of narrative . [...] He describes specifically the origin of Aragorn and being ‘astounded as slowly the revelation of the majesty of his lineage . and the weight of his doom unfolded’, and being particularly fond of writing this perilous kind of character: ‘if you become slack . and treat them as something soft (like India rubber) you find that that is only insulation covering a live wire connected with a dynamo - and you get anything from a smart titillation to a severe shock’.

This part is the most interesting -- but also sounds the least like Tolkien. Amazing that there is no picture of the letter, or at least some sort of guarantee of authenticity, considering the asking price. That aside, though, I wonder if there's much more here than Tolkien expressed elsewhere, even in particular of Aragorn in #163: "Strider sitting in the corner at the inn was a shock, and I had no more idea who he was than had Frodo..." and so on.

the trilogy’s non-alignment with any existing religion

I'd be surprised if this was anything substantially different from the idea expressed in #131: "Myth and fairy-story must, as all art, reflect and contain in solution elements of moral and religious truth (or error), but not explicit, not in the known form of the primary 'real' world."

All those topics in a mere 1000 words? I reckon the letter to Auden is at least three times that length. Twenty-five thousand my furry foot.