Socony Vacuum issued two types of Lubrite brand motor oil cans in the late 1930s and 1940s; the "plain" Lubrite and the "Standard" Lubrite where the word "Standard" appeared above the word "Lubrite" on the can. Does anyone know why there were two types of labelling? I assume the "Standard" had something to do with Standard Oil, any ideas out there? Thanks a lot.