I have found two stock buckles, one a stock clasp type and the other a typcial buckle, but both seem to be much more decorative than the average shoe buckle, non silvered that is. It might be possible it could be a stock buckle, but I somehow think they did tend to be more decorative than a knee or shoe buckle.
Mike, I liked the photos of the woman and child wearing buckled items. Hard to tell sizes, but perhaps some buckles thought to be knee buckles could in fact be a child's shoe buckle, unless the shaft location I noted on my examples is rather standard, that a shoe buckle would have it running across the width and not the length. (Hmmm, a square one would be a toss up!

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Don