Jeff,
1950 production numbers by truck model are available but I have not seem numbers for 1949.
21GPG12158
21 = Janesville, WI assembly planr
G = 1949
P = 3100 series truck (1/2 ton)
B = February assembly month
12158 = the production number 11158th 1/2 ton truck off the assembly line that year (I think that the count started at 1,000, so 1000 is subtracted from the number on the plate = 11158 - someone will correct me, if I am wrong)
Tim
The following are crude estimates based on mismatched sources of production numbers:
423,000 total trucks sold in 1950 - 6.55% (~28,000) were 1/2 ton 3105 Light Duty Panel
337,000 total trucks sold in 1949 - est. 6.55% (~22,000) were model 3105
