The Socher article is available at Zembla.
http://www.libraries.psu.edu/nabokov/socher.htm (unless you want frames)
As far as I can see, it doesn't argue that Frost is the model for Shade, but rather that Frost's poem "Of a Winter Evening" was an important source of inspiration for Nabokov.
Speaking of winter, if Yvor Winters was the model for Shade, I wonder how Nabokov felt about reality's having pre-empted the Frost-Winters pun.
R. S. Gwynn asks whether New Wye isn't supposed to be Ithaca. I would ask whether it doesn't depend on the definition of "supposed to be". I can't dispute that Wordsmith is very much like Cornell, though I don't know enough to see any specific clues beyond the hotel school. There are other links between Ithaca and New Wye, which I know about mostly from VNAY. On the other hand, it's clear from the flora and fauna and corroborated by the name Botkin (as Victor Fet pointed out) that Nabokov did have "the latitude of Palermo" in mind too. If there are any geographical resemblances between Ithaca and what little we see of New Wye and environs, I'd be glad to know about them.
To Tom Rymour: Tiger's eye or tiger-eye is sold in all American gem shops, too (based on a very small sample). The Wikipedia article says most of it comes from South Africa, though.
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