No, glass samples. It was stuffed with a variety of rolled-plate (textured glass, like what they used for the Carnival series of trays and handkerchief vases) in various thicknesses and other samples (coloured, plain, heat-resistant, etc.) so that the salesman could show prospective clients. I have quite a few from Pilkingtons and dozens of different samples (some of which may be Chance). Some time in the future Denis and I will be cataloguing them.
Funnily enough I'm pretty sure this is the box I saw being sold on eBay.