Any idea what this is? Found at old house site in Virginia. It is size of belt buckle. There was a very small attachment that broke off as shown. No clue what this is...
I think you're right about it being buckle. My guess would be 1920's, based on the deco geometric style. And if I'm seeing it right that it looks like copper, I'd bet it was silver plated. I would somewhat expect there to be a makers mark if you clean it up.
Personally I would apply a thick coating of ketchup and let it sit overnight. It cleans copper well, due to the salt and vinegar reacting with copper in some way I don't understand. However if you leave it on too long it will begin to erode the makers mark, as well as the details of the wreath in the front. Others could certainly have better ideas.