I first met Dave when my wife and I went to WV Show back in 2005 time frame. He was very friendly as we toured Jabo. Got quite a few souvenirs from him at that time. So sorry to read of his passing. Yes, the loss of a great marble legend.
Those are just distributors, not makers, although obviously a maker could be packaging their marbles. I have seen some similar headers/labels with Made in Japan on them so the distributors bought from Taiwan, Japan,....