I recognize that it is brass. I looked for info on what type of insert might have fit in that space (if it is a space) but I found almost nothing. I'm just providing possibilities...
If you're finding CW relics around it, I feel it's more likely part of a period tea kettle than a part from a late 19th C Naval artillery piece.
Yeah I was thinking the same. I believe this would have been Hood’s Unit camped on that hill. But the union did charge and I believe they also took the hill. I’ve have a call into an old school machinist. If it is a bit he’ll know. Thanks again