That’s so cool! It looks like it’s a German coin? I’d have expected Dutch, but the words on the reverse don’t seem to be in Dutch.
Yes, its also from Regensburg. It commerated the Peace Treaty of Westphalia that ended the "Thirty Years War" in 1648. Regensburg was Imperial City in HRE/ Germany today. They are nenowned for their "city view" coinage. These were struck under Holy Roman Emperors as definative issues, from 1/4 Dukat too AV 40 Dukaten. I only have the smaller version.... To show how prices went ballistic, I got mine for 1900E, recently one sold for 28K euros.
By a small margin, the most I have paid for a foreign coin was this 1813 British military guinea. These pieces were issued for use in Spain when the British were fighting Nepoleon. And this is the previous coin's cousin, the first British sovereign.
The British soldiers were well paid, but for putting your life on the line, a AV Guinea is not enough.