I found this yesterday near where I live in New Jersey. I used my MXT with an 6" Excellerator DD at about 6 inches. Can anyone can confirm that it could be from around the 1800s or earlier. General Washington's army was camp here for a while. The middle piece does move about 1/4 of an inch. There is some patina showing. Should I clean it (and how would I do that?) or just leave as is?