Could you please post a picture of the lever as well?
Assuming it has a rather standard looking lever, the pen is from 1920 through the mid 1920's. The arrows and message about the screw cap makes it on the earlier side of that date range. Swan introduced lever filling pens about 1919, and the first year they used a split lever that looks like a broken lever to most people who have not seen it before. They quickly moved on to a standard lever about 1920.