Pyrex was not used for gas pump cylinders to the best of my knowledge back in the 20's. There was no need for glass with those physical characteristics. It's more expensive to make.
There were a few vendors (I'm included) selling them for pumps in past 10 years or so since one of the major suppliers of Pyrex is on the east coast of the US.
Ron


Ron Scobie
http://www.gaspump.com or
rscobie(TheAtSymbol)gaspump.com
Phone - Six five one-653-6503