That makes sense. The price list on the cover lists Tiger Eyes, Chinese Checkers, Aqua Jewels, and Dulites. I wonder if the Dulites in my box are the big ones. I thought that might be the case. I'll post pics of the box etc. in a bit.
Sorry for jumping in so long after this original post, but there doesn’t seem to be a lot of information out there about this box. I’m new at collecting marbles, but I have one of these salesman boxes. Mine is exactly like this one. The marbles in the big section have three colors plus white. I attached a photo of that section of my box.