Nate, you were right--the motor is easy. Actually, I cannot find the Motorcraft part number, or guess how it is translated to Ford part numbers--but at least it led me to the -19805-B parts (used for under-dash AC in Fords). There was no logic in the exposed shaft on the back, everything else I saw was covered--so my guess (without explaining why..) was that originally the rear shafts were simply trimmed off the dual-fan.
Will keep looking for the fan blade...my bet is when I find it, there will be a motor attached to it
Lee