US patent D134289 S is for the "gear reduction unit" part of this 24V electric riveter/drill. The company it was issued to was the Dumore Company of Racine Wisconsin which worked closely with the Glenn L. Martin Company at that time. Nov 10, 1942 is the publication date for that patent. All of the above information came from the label attached to this unit. It also shows GLM part number: A371206, Serial number: S-80801, Spec number: 5277, Volts: 24 and Amps: 20. I would love to hear from you if you can shed any additional light upon this tool. It is definitely prior to the Lockheed Martin Company. From the information I gathered this tool was developed in the late 1940's and early 1950's for aircraft assembly. It is 8.5" in length, just over 6" tall and 3.5" wide.