I can't imagine what CSM stands for, but they were one of the many companies that produced decorative chalkware "radio lamps" in the '30s-'40s.
Stylistically similar to many ceramic TV lamps to come, CSM's ship is detailed and nicely colored. Photos courtesy of James and Claudia from Mount Vernon, Ohio.
|I believe this bulb is as old as the lamp!|
|It is marked on the back, © CSM 1935.|