I finally found Alitalia seat maps on line. They aren't included in seatguru, seatexpert or the Alitalia website, and many other sites indicate the maps aren't available online. They're on the corporate alitalia site. The most common US-Italy plane, the 767-300, is at
http://corporate.alitalia.com/en/fleet/b767200er.htm

go thru http://corporate.alitalia.com/en/fleet/index.htm
to find the other seat maps.

Now, a question- when I book through the Alitalia website, is there any way to tell the ticket class before I purchase the ticket? (very important for figuring my Delta MQM's). All they say is "cabin class: coach" or coach Y biz Y, but that "Y" seems to mean "Yes"; I just booked one that showed "coach Y" but I actually got K outbound and M return.