Aslan as an alternative version of Jesus as the form in which he may have appeared in an alternative reality?

Question

The Wikipedia article about The Chronicles of Narnia contains the following statement about Aslan:

C. S. Lewis described Aslan as an alternative version of Jesus as the form in which he may have appeared in an alternative reality.^{[28][citation not found][29]}

Reference 28 in the above quote is Walter Hooper's C. S. Lewis: A Companion and Guide, which apparently does not support that statement (or a Wikipedia editor didn't find it due to a missing page number). Reference 29 is an article on LitCharts.com, which may not be a valid source, since it might have used the above Wikipedia article as a source, thereby creating a circular reference.

So where did C. S. Lewis describe Aslan in the way stated above? The source needs to be more specific than the statement that Aslan is an allegory of Jesus.

Answer 1

Already answered over here: In-universe, is Aslan actually Jesus? (my highest-voted question on the SE network). There's two explicit quotes from Lewis's letters, and one very heavy implication in the text of the Narnia series itself, to show that Aslan is not only an allegorical retelling of the Jesus story, but, within the world of the Chronicles of Narnia, he actually is Jesus taking on an alternative form in another world.

• No, of course it was not unconscious. So far as I can remember it was not at first intentional either. That is, when I started The Lion, Witch and Wardrobe [sic] I don't think I foresaw what Aslan was going to do and suffer. I think He just insisted on behaving His own way. This of course I did understand and the whole series became Christian. But it is not, as some people think, an allegory. That is, I don't say "Let us represent Christ as Aslan." I say, "Supposing there was a world like Narnia, and supposing, like ours, it needed redemption, let us imagine what sort of Incarnation and Passion and Resurrection Christ would have there." See?

  _{-- From a letter of C.S. Lewis, quoted here.}

• As to Aslan’s other name, well I want you to guess. Has there never been anyone in this world who (1.) Arrived at the same time as Father Christmas. (2.) Said he was the son of the Great Emperor. (3.) Gave himself up for someone else’s fault to be jeered at and killed by wicked people. (4.) Came to life again. (5.) Is sometimes spoken of as a Lamb (see the end of the Dawn Treader). Don’t you really know His name in this world. Think it over and let me know your answer!

  _{-- From a letter of 3 June 1953 to a young girl named Hila Newman, quoted here, regarding Aslan going by other names in other worlds including ours.}

• "There was a real railway accident," said Aslan softly. "Your father and mother and all of you are - as you used to call it in the Shadowlands - dead. The term is over: the holidays have begun. The dream is ended: this is the morning."

  And as He spoke He no longer looked to them like a lion.

  _{-- From the end of The Last Battle. Indirect, but pretty clear by implication that Aslan actually is Jesus within the story, not just an allegory thereof.}