Found by Silodrome, the car is listed by Moto Exotica out of St. Louis, Missouri. According to Moto Exotica, which sources a clip from the book "Running with the Champ" by Ali's close friend and car guy Tim Shanahan, Ali had set out with Shanahan to buy a new Rolls-Royce (Ali loved his Double-Rs) during his time living in Chicago. The two visited European Imports in Lake Forest, Illinois, with the intention of buying a Kelly Green Corniche and possibly a Mercedes-Benz SL for Ali's wife, Veronica Porché.
To Ali's dismay, the dealership did not have any SLs in stock, so this Alfa was suggested as an alternative. Ali purchased the car, brought it home, and ran into yet another issue. Porché did not know how to drive the car's manual transmission, and apparently didn't have any desire to learn. So the car mostly sat, with the exception of some rare errand runs by one of Ali's assistants.
After a short time passed, Ali learned that Shanahan's personal car had broken down. In a situation that perhaps suggests destiny, Ali then gifted the car to Shanahan, who has owned the car for 40-plus years up until its sale to Moto Exotica.
With about 80,000 miles, it has some wear and tear, such as a small crack on the dashboard, but it's in solid overall shape and recently received a respray. Plus it comes with the real registration with Ali's signature on it.
Check out the full photos, video, and descriptive listing at Moto Exotica.