Both of your units were introduced in 1928. This was during the time that Bennett was only making lube and grease equipment. They didn't introduce their first gas pump until the following year. Equipment such as yours was usually made for 15-20 years, I haven't researched them enough to tell you whey they were discontinued. Sorry, I cannot tell you when yours were made as they didn't track lube production. If you are interesed in original sales literature, ads or possibly a parts manual email me.
Jack Sim jhsim@swbell.net
Author, 1st & 2nd editions of Gas Pump ID book, 3rd edition is now available at
www.gaspumpbible.comAir Meter ID book also available