I'd guess the 1950' or 60's. I have a box of their chips someplace; might have a patent date. Here are two pictures including the instructions. I bet someone could guess the age from the style of the printing of the instructions.

http://www.amazon.com/gp/product/images/B001CZY6AW/ref=dp_otherviews_5?ie=UTF8&s=sporting-goods&img=5

http://www.amazon.com/gp/product/images/B001CZY6AW/ref=dp_image_0?ie=UTF8&n=3375251&s=sporting-goods

Robert