Three crowns are from the Swedish coat of arms and I can read IOHANN. There is a King Johan III of Sweden, maybe this is from that era?
A pic from the Swedish Wikipedia and the text IOHANNS on the top right looks like it matches.

I don't know anything about hammered coinage but the era of his reign matches the era for hammered coinage.
A pic from the Swedish Wikipedia and the text IOHANNS on the top right looks like it matches.

I don't know anything about hammered coinage but the era of his reign matches the era for hammered coinage.





















