What is this for?

At the World Fairtrade Fair this morning, there was a stall for Tools for Self-Reliance, who refurbish tools donated to them to send to third-world countries to help them become more self-reliant. They also sell refurbished tools here to raise funds.
Tony, who runs the Crickhowell branch, showed me this tool, and asked me if I could tell what it was. I was hopelessly wrong. What would you say?