Lettered Series Gauge Colors – All were white face gauges until sometime in 1952 when the supply of white face gauges ran out and John Deere switched to black face gauges. Below are the approximate serial number breaks:
- Styled A changed to black after serial number 700200
- Styled B changed to black after serial number 306600
- Styled G changed to black after serial number 60700
Keep in mind these are the serial numbers of when the change was scheduled for, but white face gauges 
were installed until the stock was diminished. Tractors with serial numbers not listed probably changed mid 1952 to black face gauges.
JR Roberts