1960s? Hanging Lamp

The globe on this lamp is 13.5" long x 7" in diameter and the lamp is 19" long, assembled. The only writing is on the Leviton roller switch. The switch is bidirectional, a rocker switch, rolls forward to turn on and rolls back to turn off. It is not a rotary switch but looks like one. This lamp has been hanging in my basement since 1997 when I bought my house, left by some generation of previous occupants. I've never really looked to closely at it but today took it down from the rafter where it has been hanging with the chain coiled around it, cleaned it up and tested it. It works! There is an "antique" flourescent bulb in it that also works. The receptacle is ceramic and the chain is brass plated. Wondering what the age might be, so I can make a guess on whether the globe is American made or imported.... Thoughts welcome!