The mystery of the missing oil?

1920 carbs have an issue of the PCV port in the base of the carb getting plugged up. Check and see if you have vacuum at the valve. If not, then check the port on the carb. If no vacuum, remove the carb and clean the port from the outside, and from the carb base (1/4 inch drill bit by hand). Also make sure the PCV hole in the intake manifold is clear, and the base gasket is installed the correct way.