I don’t know anything about Pyrex – zip, nothing, nada! I rarely purchase it, although I am fascinated by the array of colours, shapes and designs that Pyrex has come in. Everyone has owned a piece of Pyrex sometime in their life.
There are a number of Pyrex sites/groups on Facebook. I joined one for awhile, but since Pyrex isn’t a great interest, I dropped out of the group. But likely great sources of info for someone else.
I was attracted to these little bowls as I do like restaurantware. I like the heavier pieces of glass and I am guessing that the intended purpose for these pieces was to be used in a restaurant or heavy use setting. Hence the ‘Double Ware’ name! But, who knows, I could be completely off base? If someone does know more about the history of these nappies, please share.