(click on pictures to enlarge)
The Cruver Manufacturing Company was located in Chicago, illinois and produced a variety of advertising items. On December 31, 1920, Curtis L. Cruver filed a patent application for a pencil clip with a built in advertising button, which was awarded in 1924. View here.
The February 1932 issue of The Rotarian contains one of the company's advertisements, which advertises, among other celluloid items, "Also a Cruver propel-repel-expel mechanical pencil, guaranteed for 100 years, sample sent imprinted with your name for 60c. We believe it to be the best pencil in the world." The company's address is listed as 2456 Jackson Blvd., Chicago Illinois.
The Dur-O-Lite and Autopoint design influences on this pencil are very apparent, and since all three were located in Chicago I don't think it's a stretch to say Charles Keeran had something to do with this. However, this pencil has a conventional screw drive rather than the threaded drive found on Autopoints and Dur-O-Lites. A brass inner barrel is necked down near the tip end to snugly fit around the screw -- sort of like a Welsh Mechanism with the barrel friction fit around the screw rather than a bell on the screw friction fit into the barrel.
Research on this one continues.