WOW great finds, not many people collect horse things, mostly because they are so hard to find and very expensive. In the southwestern U.S. a lot of the 1980's cowboys used Mexican spurs and spade bits, good ones are hard to find. In the mid 1900's they came back into style and one of the artists at making a spade bit was a fellow named Garcia, his bitsd will bring over a thousand dollars now.
Are you sure that the bottom one is a buckle? I found one a while back and just tossed it with the rest of the "junk" that I have. I thought it was a trunk handle. Either way, very nice finds!