In the LotGK thread in the Silver Chair section, hansgeorg alerted me to the possible influence of Andrew Lang's fairy tale books on Narnia, and I think I found one possible instance. In the Swedish tale "King Lindorm" in the Pink Book, the eponymous lindorm (= wingless dragon) has to remove several of his skins (seven in the tale) to become human. Also, it's prefaced by a matter-of-fact request that no one had thought of before, which also sort of evokes the way it comes across in VDT...

(It's available online, but I'm refraining from linking - you can find it in several places, anyway.)