These are in the current price guide, but I'm not sure they were made here.
They were found in Belgium and England.
The left one is embossed "PYREX BRAND" and "66000" in respective wire groove ends.
Also has a sandblast marking on one flange of "AP53024"
Middle one has one of it's flanges polished smooth instead of a birthmark button like the other two.
Middle one and Right one have no embossing.
Colors L-R are Light Straw, Clear, and Straw Tint.