A few weeks ago I purchased this vintage postage scale at a local shop. It has been tole painted which I wish it hadn't been but I still enjoy the chart on the scale.
It is a postal machine manufactured by the Triner Manufacturing Company in Chicago, Ill.. Local first class mail was 2 cents per ounce and air mail 5 cents. There is no date on the machine.
After doing some research on Wickipedia for the history of postal rates, the machine could be as old as 1919. The rates on the charts match the dates on the machine.