Sticky,a mount is what it says it is.It would be something decorative mounted on,say on a leather harness,which is what i think yours is.The two points you can see would have gone through the leather and bent over the otherside so it wouldnt come off,maybe the leather has rotted away and thats all which would be left over.Mounts have been used for hundreds of years and still are today,here,s another example of one,this one is from the 1700,s.As i said,a mount could be on anything really,clothing,a belt or a bucket,whatever they wanted to put it on.The badge on your car which shows the make or model is a mount.