The 1955.2 was the first year for the
Cameo Carrier, Model 3124,
as Tim posted above.
All 3100 series, 1955.2, are H255 which makes it difficult.
A factory installed vin tag for the
55 Cameo, should at least be H255.
There were a little over 5000 or so produced in 1955.
http://auto.howstuffworks.com/1955-1957-chevrolet-trucks4.htm