Mike, I'm not dead sure if at that time the maker was called just "Asti" instead of later "Gate Asti", the motor number is MP3920-31... The overall number MP3920 was apparently used for years and years, the -xx number will vary with the actual spec. But its entirely likely that yours is fine, or that any electrician could clean it up.
I also guess that the UK mini fan blade would work. The Goose heater box is 'shared' with the Mini Innocenti (the Italia version of the Mini), and then only the chimney is added on the IPRA Goose box. Somewhere on my shelf there I have NOS motor and also a used Innocenti box...
For the AC, I think the motor is a Behr, made in Ft. Worth TX 
. But that basic style was used for decades (esp, 80's Alfa Spider), and even I think the retrofit Pantera AC fan solutions just may fit. Trying to find genuine 60's AC components is damn difficult, it just seems that not many cars, really, had AC...Lee
ps. btw, I think your valve covers are pretty cool, got a picture to share?