I sculpted the shape in modeling clay first, then took a plaster mold from that. I bought an electric melting pot, and melted down some old pewter Star Wars christmas ornaments I had lying about. The first two production runs sucked, so after melting down all my first attempts, and re-doing the clay model and plaster mold, I came up with this one.
After casting this, I played a game of "let's see what I can melt in this thing." Fun times.
Today I got the soapstone I'd ordered - future molds will be carved from that, instead of cast from plaster.
My next project is buttons. I want to replace the plastic buttons on a 1800's vest I bought recently with some pewter ones, with either gears or skulls embossed on them. Maybe both ...