I second at least the direction of Jack's speculation. While vintage spark plug gap and ignition points gages did include wire types, either bent in a semi-circle on the outside of disk (e.g., Auto-Lite) or folded out of a metallic case just like the more common leaf-type feeler gages, they were typically rather small in range (less than a dozen wires). If I'm interpreting the photos clearly, there are 50 pieces with 2 different gage sizes on each piece for a total of 100 gage sizes! And I am guessing that each one is a decimal equivalent. That's en entire magnitude of sizes. Far too many for any one mechanic, even an ignition specialist working on a variety of cars and trucks.
I was going to guess that it is something a jobber (someone planning a project) or a salesman would carry around with him. But I like Jack's theory.