Originally Posted by Gerbie

It looks like an old tracing tool. I used these way back when with a carbon like paper you could buy, I don't know if they still sell it or not. The paper was in a package with several different colors. I would use the paper to lay on darts and other areas that I wanted to show up when I was just generally sewing, then use the tracing wheel to run over the lines. The sharp points on the blade cut through the carbon paper leaving marks. I still have a couple of these, not sure if I still have the paper or not. Now am I telling my age or what lol. Gerbie