Looking at this old Gallery Mint website, I scroll down almost to the bottom of the page and see that they make "high relief dimes" which are "slightly larger" than a real dime, and "very thick due to the extreme relief". I think this planchet would fit the bill for such a replica perfectly.
It says "Gallery mint" along with an odd symbol on both sides of the rim. I'm unsure what the symbol is.
I think the symbol is supposed to be an old-fashioned screw press, like was used a couple of hundred years ago to mint coins. See this Wikipedia article.
My questions on this coin, Since it is a blank, does that give it a premium?
I wouldn't think so. Looking through some of the other archived pages, there's a lot of "mint errors" for sale; no doubt some of these were deliberately made for sale to error collectors. Also saw a couple of other blank planchets for sale (for their replica hammered ancient coins). From this I'd assume that "errors" could be made to order and that they'd happily sell you a blank planchet for bullion value.