The name is odd, because you would expect Silversmith to be like Coppersmith, but for Silvers. That card would be too powerful.
On this one though:
+2 cards, +$1 is a decently powerful effect, though the mix can be hard to judge.
+$1 for discarding Treasure is actually useless most of the time. There are some edge cases -- Potion, Horn of Plenty, even Bank, not to mention draw-to-X cards, but in general it is a "nothing" choice which you would pick if you don't have something better to discard. (Oh, Qvist's Grand Market edge case is a good one as well, as is soulnet's Tactician.)
Discarding a Victory card can be great for engines.
The possibility of making it non-terminal is very powerful too. I like Qvist's suggestions for making it a $5.
Your new version seems too powerful. The Treasure option is especially powerful as it is not difficult to flood your deck with silver, nor does it hurt you to do it.
I think it might be OK if you drop the on-gain.