I looked at brooches but all the pins were set inside with c clamps. I looked at all the hinges on pocket watches. It's annoying as I want to know what it's off lolJust my 2c but it could be a pocket watch or possibly a ladies brooch?
Not sure if it's worth the effort but the flat spots on the edges look like they are holding the centre in, maybe if you were able to unfold them with a seal pick you might be able to get the centre out. Just thought it might add some clues to what this is..