Weeds,
Do you have ideas for how to determine if your truck is a 47-2nd series or a '48?
Here are a few features to look for. Maybe there are other features that people will post?
1. '47 had 3-sp transmission with floor shifter (no column shifter - no holes in the steering column for column shifter). However, 4-speed transmission trucks also did not have holes on the steering column. Thus, if you have holes in the steering column for a column shifter, you have a '48 truck or the steering column might have been replaced with a later 3-speed's column.
2. '48 had the 3-sp transmission on the column. Thus, there was a floor mounted parking brake pedal (to the left of the clutch pedal). I am not certain, but most likely the 1947 1/2 ton frame did not have the channel in the frame cross-member that is needed for routing the foot-pedal parking brake linkage rod.
Maybe other people will correct me and/or post other things to look for.
Tim