VINs were established to clarify country of origin, manufacturer, powertrain, year of manufacture etc with the last 6 digits being vehicle serial number...VINs were not used prior to the late 60s, but data plates that contained manufacturer specific codes for powertrain, trim, paint etc as well as serial numbers were used...these trucks had a serial number and a model designation, if ya wanted more info you would have to get a build card...and for quite a few states, when assigning VINs became mandatory, these old trucks were assigned their engine number, not the serial number, so the VIN on the title could possibly not be found on the truck at all if the engine is swapped out...my '48 title has a T142 engine number, but the truck has had a Plymouth engine in it since '68 or so...so VIN kinda muddies up the water a bit whereas serial number is definitive