Chicago Steel Tank Co. was primarily a TANK manufacturer. While my book lists that they may have made at least one pump around 1921, this is only conjecture. I took that information from a magazine stating that they were offering a pump at that time. Chances are, they were offering a pump made by a pump manufacturer, and not one that they made them selves. This was true of many tank manufacturers prior to 1925. They would be in the tank business, but to supplement their business they would offer a package, a tank they made and a pump from a pump company they represented, in this case G&B.
Some of these pumps were listed as G&B and some were renamed for the tank manuf. It mostly depended on how many they ordered.
Jack Sim
Author, 1st & 2nd editions of Gas Pump ID book, 3rd edition is now available at
www.gaspumpbible.comAir Meter ID book also available