Instructions
Locate the brass or nickel plate on the front of the cash register. It is usually located just underneath the glass window. It will have a series of numbers on it.
Look at the model number on the brass or nickel plate. It is generally a one-, two-, three- or four-digit number on a brass tag on the front of the machine. Close by should be the serial number; it is a five or more digit number generally in the 100,000s or millions. If the serial number begins with an S, the machine was reworked and resold by NCR.
Check the front of the cash drawer. Many National cash registers have the name "National" across the front. The logo should be raised and made with the same material as the rest of the cash register. The wood registers have the word "National" stamped in gold.
View the serial number chart (see Resources) to determine when your National cash register was manufactured.