Alfa Romeo's primary production facility, the Arese complex on the outskirts of Milan,ltaly, now lies all but abandoned, weeds reclaiming the SOD-acre site, assembly lines relocated to Naples and elsewhere. In a remote corner of the grounds, though, two buildings remain in use. One bustles with Alfa offices. The other, dark and unremarkable from the outside, safeguards the entire sheetmetal saga of Alfa Romeo. TI,e Historical Museum, or Museo Storico, spans six floors and houses well over 100 automobiles-one example, it's said, of every road and racing model produced since the founding of Anonima Lombarda Fabbrica di Automobili- "A.L.F.A." -in 1910. The museum is open to the public, free of charge, but you must book at least two weeks in advance (visit alfaromeo.com). If you're headed to Northern Italy, do it.Right here is a carriage-like, brass-Iamped 24 HPTorpedo, one of just 300, the original A.L.F.A. Over here is a 67-horsepower 20/30 HP ES, badged "Alfa Romeo" (after entrepreneur Nicola Romeo took over the company in 1915). There's a pristine 1966 Duetto, the libidinous roadster Dustin Hoffman drove into immortality in "The Graduate" (it's also the last car, I learn, designed by Battista "Pinin" Farina). I'm drawn to the race cars. Among the exhibits is legendary engineer Vittorio Jano's single-seat, open-wheel P3, the machine in which Tazio Nuvolari humiliated five factory Mercedes and four Auto Unions-and the entire Third Reich-in the 1935 German Grand Prix. Also here are a 1S8 "Alfetta;' winner of the first Formula 1 World Championship (in 1950, with Nino Farina), and its successor, the 159, which carried Juan Manuel Fangio to the Fl title in 1951. My guide pulls a swordlike dipstick from the cockpit. Embossed into the metal is the name "Fangio."Almost every machine in the Museo Storico is kept in running condition (the cars regularly travel to vintage events all over the world)-as today I find out first-hand. At the nearby Balocco test track, I get a ride in an 8e 2900 B Speciale, the very car that was 100 miles in the lead of the 193824 Hours of Le Mans (a race Alfa dominated in the 1930s) when a valve broke an hour from the finish. The old engine pulls hard; the gated four-speed shifts betterthan that of a 1980s Ferrari. The car is valued at, oh, six million. It's worth bearing the above in mind as Alfa returns to the u.s. in force in 2009(brass fitting , brass ball valve)