And here's a picture:

For now, try not to look too closely at the last word which doesn't quite seem to match the transcription that most experts claim. Let's pretend for the moment that such details aren't important and if it helps, drink some whiskey to dumb your mind down. What many academics usually do to work around this pesky detail is to just pretend that the word isn't there. Oh look, poof! It's gone: Bisang, Aspects of Typology and Universals (2001), p.122; Bonfante/Bonfante, The Etruscan Language: An Introduction, Revised Editon (2003), p.205; De Grummond, Etruscan Myth, Sacred History, and Legend (2006), p.149. As you can see, the last word is easily forgotten in the shadow of a mighty god named Selvans Sanchuneta.
But who is Selvans Sanchuneta? Nobody can say. In a nutshell, it's another "mystery god" invented by an unchecked department of academia who use pseudolinguistics to invent a long story that will fill up a book with their name on it. Colonna sought out to prove that an otherwise unknown hapax sanχuneta refers to an obscure Roman god Sancus. No particular reason, really, other than the fact that they begin with similar sounds. Of course, academics can't just admit to coining new folk etymologies because then they'd look foolish, but in the end it really is just another modern game of word association. While many claim that Sancus is of Etruscan origin, the claim isn't founded on anything substantial and could just as easily be etymologically related to Latin sanctus "holy" and thus of Italic origin. However, all of this misses an opportunity to intelligently analyze the grammar of the inscription. The word or name sanχuneta is in fact in all likelihood two items: sanχune-ta "the [sanχune]" (with trailing enclitic demonstrative -ta functioning as a definite article). It appears then that the status quo is yet again way off-base. There is no question that the first word is the god Selvans, but the second word claimed to be part of the epithet of this god is too problematic to be considered secure. What do we make of the unanalysable -ne or -neta ending if we are asked to entertain the notion that Latin Sancus begat Etruscan sanχuneta?[1]
Now after you've drunk your whiskey to kill the pain, what about the last word? Well, that's another kit-and-kaboodle, isn't it? When you look at the picture above, we see clearly a zeta (which looks like a modern "i" in serif font) following the epsilon and the trailing rho and alpha are upside-down. Ignoring the change in direction of the text, we would have cvezra, not cvera. Nonetheless, all the Etruscologists continue to state that the word here says cvera, a reflex of cver assumed to mean "image" by some.
I wish I had answers, yet all I have is one question after another. Nevertheless, a good question is always better than a shakey answer.
NOTES
[1] Dorcey, for one, openly questions the validity of similar claims by Pfiffig linking it to a title Sanctus, albeit it in a cowardly footnote. (see, The Cult of Silvanus: A Study in Roman Folk Religion (1992), p.11, fn.17)
UPDATES
(Nov 28 2007) We could perhaps in theory salvage the idea of Silvans Sancus but only if one analyses the phrase Silvans Sanχune-ta as underlying *Silvans Sanχuna-ita "(The) Silvans of Sancus" (with the deictic form -ita rather than -ta to explain e < *ai). One would then presume that Sanχuna is an adjective formed on a hypothetical Etruscan name *Sanχu "Sancus" using the suffix -na which is used in other adjectives and nominal derivatives. Even if this is so, I'd love to see the final word explained properly to finally tie this all together.