There is no actual makers name on the pen/pencil but the nib says “E.S. Johnson, New York, No. 4”. The mechanism is interesting on this one as the pen is a slider but to use the pencil you first extend the barrel simply by pulling on it (which can also be used as an upper extension when using the pen) and then twisting the small knob at the end extrudes the pencil nozzle. This design was actually filed by John Rauch (patent # 91665). According to Jonathan Veley, Rauch and Mabie Todd both had examples of this design but this one is unmarked.
Nib is stamped "E.S. Johnson, New York, No. 4"