This was a quickie on long delay thanks to the UPS holiday thieves. Took 3 weeks to get my brass pin stock thanks to them. Anyway, hard brass scales and pins with a phosphor bronze liner between the layers. The peening is tricky on these. You basically tap and check the tool tension, then tap and check the tool tension, over and over until each tool feels just a bit tight. They'll loosen up over time and all but two of the pins came out nearly invisible. I can live with that.