Further correspondence with Collette at Chemex creates more mystery about whether the blue stamp preceded the green. My entry is revised above.

Another online listing shows evidence that green label ones with embossing not arching the Chemex name over 180° is later production than blue label with what appears to be a cruder embossing mark. This one is 13 cup. It has three footings. And the green label is on the bottom like we see on later versions that were hand-blown but not embossed.