I have two Craftsman screwdrivers that do not have the typical "WF" or "PR" marking. One is a 1/2" flat blade with no number and just an "F" mark. I have never seen another Craftsman 1/2" flat blade screwdriver. It is quite "butch" as we say in the Theater/Entertainment lighting industry. I suspect it may be made by Millers Falls due to its similarity to one posted by bmwpower last week. The other one is marked "Super-Tuff" and has G with a circle around it. Both screwdrivers are the typical Craftsman red, clear and blue.
I may conduct some research to determine which out of the four OEM types I have are the smelliest.