Hooookay! Today I found 4 unlabelled clear glasses in this style, which I bought to compare with my amber Stuart ones. The clear ones are, I think, the Dema machine-made ones.
The clear ones are much thinner and lighter than the Stuart ones. I weighed the clear ones and each one is 100-101g, my scales aren't accurate enough to get closer than that. The Stuart ones vary between 226g - 255g, so much heavier.
Chris can you weigh your blue ones for comparison please?