Crikey - talk about picking the obscure one.
Etruscan figures? Heh, no wonder you're having a hard time searching.
These seem to be the most comprehensive sources I can find online:
[url=http://www.pantheon.org/articles/v/vanth.html]Vanth at Pantheon[url]
Vanth picture Vanth explained in modern hip speak
Not much, really.
In fact, you've posted more information than any of those sources have.