Fangio's in his old Mercedes W196 car; that has to be from either 1954 or 1955. There were two types of W196s: The Streamliner, used at high-speed events, and the one in the video with all the aerodynamic fairings removed.
Brabham appears to be in his old Brabham-Repco (type number BT24 or BT26); it's from either 1966 or 1967, since I don't think many changes were made. Those cars were Constructor's Cup champions in both seasons.
If I'm not mistake, there appears to be a white with blue-striped Maserati 250F in racing in the background (anywhere from 1954 to 1958).
The last car looks to be a Ferrari sports-racing car from the latter half of the 1950s; a TR, perhaps? I'm not good at picking out those type of cars.