As I understand it, this is a silver strike from the dies for the gold 1 1/4 ducat 1764, for the coronation of Joseph II as Holy Roman Emperor in Frankfurt. I found this similar listing in MA Shops:
This sort of coin is usually considered a token or medal. Coronation token.
They were often minted in gold and silver and it is a choice of the catalogue and/or seller to name it with a coin denomination.
A 1 1/4 ducat is probably 4.4 g gold.
4 g silver depends so much on the fineness that it is a bit difficult and unnecessary to try to find an equivalence.
The size you mention is the 10 Kreuzer coin butt I would not call it a 10 Kreuzer.
Your coin would fit very well in the token section though. There are curently 2 other Austrian coronation tokens (many from Russia, some English etc).
Regards.
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