I’m usually not very good at this, but it looks to me that the function of the device is to hold something in place through the side loops, maybe rope or fabric. Could it be part of some sort of a loom? I’d like to see the bottom edge as well. Pretty cool whatever it is.
It doesn't appear that it was mounted to anything, and the ball is suggestive of a tapper .. such as those seen on glass cutters. I am wondering if it was a custom pattern for something like pie safe tins?