Nate, this is incredibly helpful ! I wasn't remotely thinking Motorcraft, what a strange twist. The part number on the fan doesn't seem to fit Lucas part number scheme, and all the Fiat fan I find start in the 4 million range...
Google images teases me, I find the right picture (white, 6 blade fan with center hole) responding to "Ferrari Maserati engine cooling fan OEM" but with a lost link. I've looked thru I think all the 60's Maserati, Fiat and Alfa parts diagrams w/o luck yet.
The truth is out there...

Just need patience to find it. Thanks so much for your help, again--Lee