I was born and raised in Monson and when I was a kid(70's) I found an 1868 German coin digging in my yard, I still have it and it is my oldest coin still.
Since this was a wartime coin, it is very possible it was part of someone's collection. Maybe a kid had it for show and tell and lost it. You'd be surprised to see the number of foreign coins found at school yards. Nice find.