Sorry it took me a bit to get back. I'm a fire investigator and I've been working on a large apartment fire we had.
Anyway....It's plastic. I scratched, and sanded, and did all sorts of things where it wouldn't show. Even curled a sliver off and took a cigarette lighter to it. it melted and smelled like plastic not like horn or bone. I've turned antler pens and smelled enough bone to know, i'll just have to ask you to trust me on it.
I decided I didn't like it, it looked fine but I didn't like it. So, I cut it off, tried to do it a lil at a time thinking there was wood under it. Well, there wasn't. This was a solid piece of plastic glued with nothing but a but joint to the stock. No wood under, no dowel pins, just a simple but joint.
I've ordered some pewter, guess I'll do my own. I'll put in some type of support to cast around to help hold it all together. I also ordered 2 matching wedge keys, the ones I have don't match, and one is too thick to fit. That one was hammered in and bent the plate on the far side. Only thing I could find that was the size of the one that fit was from a 1803 Harpers Ferry Rifle from TOW. nothing else was the right width and thickness.
So, the fun continues.