They are a pair of antique cut steel buckles that I bought for Charlotte at the Dress U marketplace. A littler closer of a view:
I don't know how old they are, but I feel they have the right look to work with Charlotte's mostly-18th-century wardrobe. I had thought to make them shoe buckles on a pair of shoes I'm daydreaming of making for her. Not sure if they are actually a bit small for that, but I'm going to give it a shot and see if I can make it work!