What is this tool?

[beresman]

The knife is made by Dültgen; it has two regular blades and then this...At first I thought it was meant to be a farrier's pick, but it's actually hollow...What does it do?

[Froe]

First of all, I don’t know what it is. But to me it reminds me of frame to hold another blade. Like the reinforcement on a single edge razor blade or the frame to hold a saw or file blade. The knife not look like something found at a cockfight.

Froe