Sandy Duncan had some funny tidbits in her production that Mary Martin and Cathy Rigby didn't.
For example, when her shadow appears on the wall, she says "Well, its not quite itself yet."
She says this in response to her shadow doing the opposite what she is doing, and getting stuck.
Her flying was unique, as well.
Compare her flying pictures with the others, here:
www.peterpanfan.com/ospictures.html
"The Spectacle has, indeed, an emotional attraction of its own, but, of all the parts, it is the least artistic, and connected least with the art of poetry. For the power of Tragedy, we may be sure, is felt even apart from representation and actors. Besides, the production of spectacular effects depends more on the art of the stage machinist than on that of the poet."
--Aristotle