Found at the top a ravine

These were on the surface in an area of southern Minnesota known for a tumultuous time in the 1860’s- I’ve gotten as far as assuming they were part of a horse bridle/saddle/something similar, but nothing else. I’m more of a stone artifact gal- and haven’t gotten much experience in identification of metals in reference to specific material, or dating.

Photos in hand are after a lengthy vinegar soak and soft brush. Plan to try electrolysis (?) next, if this doesn’t give me the results I want

Any thoughts on material/age/or even solid identification of what they are from the pros here?